aging

Memory loss in old age the price we pay for a large brain & a long life?

September, 2011
  • Chimpanzee brains don’t shrink with age as humans’ do. It may be that cognitive impairment and even dementia are our lot because we work our brains too hard for too long.

Comparison of 99 chimpanzee brains ranging from 10-51 years of age with 87 human brains ranging from 22-88 years of age has revealed that, unlike the humans, chimpanzee brains showed no sign of shrinkage with age. But the answer may be simple: we live much longer. In the wild, chimps rarely live past 45, and although human brains start shrinking as early as 25 (as soon as they reach maturity, basically!), it doesn’t become significant until around 50.

The answer suggests one reason why humans are uniquely vulnerable to Alzheimer’s disease — it’s all down to our combination of large brain and long life. There are other animals that experience some cognitive impairment and brain atrophy as they age, but nothing as extreme as that found in humans (a 10-15% decline in volume over the life-span). (Elephants and whales have the same two attributes as humans — large brains and long lives — but we lack information on how their brains change with age.)

The problem may lie in the fact that our brains use so much more energy than chimps’ (being more than three times larger than theirs) and thus produce a great deal more damaging oxidation. Over a longer life-span, this accumulates until it significantly damages the brain.

If that’s true, it reinforces the value of a diet high in antioxidants.

Reference: 

[2500] Sherwood, C. C., Gordon A. D., Allen J. S., Phillips K. A., Erwin J. M., Hof P. R., et al.
(2011).  Aging of the cerebral cortex differs between humans and chimpanzees.
Proceedings of the National Academy of Sciences. 108(32), 13029 - 13034.

Source: 

Topics: 

tags: 

tags development: 

tags problems: 

Whether couple’s collaborative dialogue helps spouse's memory

September, 2011

A small study suggests that middle-aged couples are more likely to be effective than older couples in helping fill in each other’s memory gaps, but effective collaboration also depends on conversational style.

In my book on remembering what you’re doing and what you intend to do, I briefly discuss the popular strategy of asking someone to remind you (basically, whether it’s an effective strategy depends on several factors, of which the most important is the reliability of the person doing the reminding). So I was interested to see a pilot study investigating the use of this strategy between couples.

The study confirms earlier findings that the extent to which this strategy is effective depends on how reliable the partner's memory is, but expands on that by tying it to age and conversational style.

The study involved 11 married couples, of whom five were middle-aged (average age 52), and six were older adults (average age 73). Participants completed a range of prospective memory tasks by playing the board game "Virtual Week," which encourages verbal interaction among players about completing real life tasks. For each virtual "day" in the game, participants were asked to perform 10 different prospective memory tasks — four that regularly occur (eg, taking medication with breakfast), four that were different each day (eg, purchasing gasoline for the car), and two being time-check tasks that were not based on the activities of the board game (eg, check lung capacity at two specified times).

Overall, the middle-aged group benefited more from collaboration than the older group. But it was also found that those couples who performed best were those who were more supportive and encouraging of each other.

Collaboration in memory tasks is an interesting activity, because it can be both helpful and hindering. Think about how memory works — by association. You start from some point, and if you’re on a good track, more and more should be revealed as each memory triggers another. If another person keeps interrupting your train, you can be derailed. On the other hand, they might help you fill you in gaps that you need, or even point you to the right track, if you’re on the wrong one.

In this small study, it tended to be the middle-aged couples that filled in the gaps more effectively than the older couples. That probably has a lot to do with memory reliability. So it’s not a big surprise (though useful to be aware of). But what I find more interesting (because it’s less obvious, and more importantly, because it’s more under our control) is this idea that our conversational style affects whether memory collaboration is useful or counterproductive. I look forward to results from a larger study.

Reference: 

[2490] Margrett, J. A., Reese-Melancon C., & Rendell P. G.
(2011).  Examining Collaborative Dialogue Among Couples.
Zeitschrift für Psychologie / Journal of Psychology. 219, 100 - 107.

Source: 

Topics: 

tags: 

tags development: 

tags problems: 

Possible treatment for working memory decline with age

September, 2011

A study has successfully countered reduced activity in the prefrontal cortex seen in older monkeys. Clinical trials are now investigating whether the drug can improve working memory in older humans.

A study comparing activity in the dorsolateral prefrontal cortex in young, middle-aged and aged macaque monkeys as they performed a spatial working memory task has found that while neurons of the young monkeys maintained a high rate of firing during the task, neurons in older animals showed slower firing rates. The decline began in middle age.

Neuron activity was recorded in a particular area of the dorsolateral prefrontal cortex that is most important for visuospatial working memory. Some neurons only fired when the cue was presented (28 CUE cells), but most were active during the delay period as well as the cue and response periods (273 DELAY neurons). Persistent firing during the delay period is of particular interest, as it is required to maintain information in working memory. Many DELAY neurons increased their activity when the preferred spatial location was being remembered.

While the activity of the CUE cells was unaffected by age, that of DELAY cells was significantly reduced. This was true both of spontaneous activity and task-related activity. Moreover, the reduction was greatest during the cue and delay periods for the preferred direction, meaning that the effect of age was to reduce the ability to distinguish preferred and non-preferred directions.

It appeared that the aging prefrontal cortex was accumulating excessive levels of an important signaling molecule called cAMP. When cAMP was inhibited or cAMP-sensitive ion channels were blocked, firing rates rose to more youthful levels. On the other hand, when cAMP was stimulated, aged neurons reduced their activity even more.

The findings are consistent with rat research that has found two of the agents used — guanfacine and Rp-cAMPS — can improve working memory in aged rats. Guanfacine is a medication that is already approved for treating hypertension in adults and prefrontal deficits in children. A clinical trial testing guanfacine's ability to improve working memory and executive functions in elderly subjects who do not have dementia is now taking place.

Reference: 

[2349] Wang, M., Gamo N. J., Yang Y., Jin L. E., Wang X-J., Laubach M., et al.
(2011).  Neuronal basis of age-related working memory decline.
Nature. advance online publication,

Source: 

Topics: 

tags development: 

tags memworks: 

tags problems: 

Older people find it harder to see the wood for the trees

September, 2011

A study indicates that difficulty in seeing the whole, vs elements of the whole, is associated with impairment in perceptual grouping, and this is more common with age.

A standard test of how we perceive local vs global features of visual objects uses Navon figures — large letters made up of smaller ones (see below for an example). As in the Stroop test when colors and color words disagree (RED), the viewer can focus either on the large letter or the smaller ones. When the viewer is faster at seeing the larger letter, they are said to be showing global precedence; when they’re faster at seeing the component letters, they are said to be showing local precedence. Typically, the greater the number of component letters, the easier it is to see the larger letter. This is consistent with the Gestalt principles of proximity and continuity — elements that are close together and form smooth lines will tend to be perceptually grouped together and seen as a unit (the greater the number of component letters, the closer they will be, and the smoother the line).

In previous research, older adults have often demonstrated local precedence rather than global, although the results have been inconsistent. One earlier study found that older adults performed poorly when asked to report in which direction (horizontal or vertical) dots formed smooth lines, suggesting an age-related decline in perceptual grouping. The present study therefore investigated whether this decline was behind the decrease in global precedence.

In the study 20 young men (average age 22) and 20 older men (average age 57) were shown Navon figures and asked whether the target letter formed the large letter or the smaller letters (e.g., “Is the big or the small letter an E?”). The number of component letters was systematically varied across five quantities. Under such circumstances it is expected that at a certain level of letter density everyone will switch to global precedence, but if a person is impaired at perceptual grouping, this will occur at a higher level of density.

The young men were, unsurprisingly, markedly faster than the older men in their responses. They were also significantly faster at responding when the target was the global letter, compared to when it was the local letter (i.e. they showed global precedence). The older adults, on the other hand, had equal reaction times to global and local targets. Moreover, they showed no improvement as the letter-density increased (unlike the young men).

It is noteworthy that the older men, while they failed to show global precedence, also failed to show local precedence (remember that results are based on group averages; this suggests that the group was evenly balanced between those showing local precedence and those showing global precedence). Interestingly, previous research has suggested that women are more likely to show local precedence.

The link between perceptual grouping and global precedence is further supported by individual differences — older men who were insensitive to changes in letter-density were almost exclusively the ones that showed persistent local precedence. Indeed, increases in letter-density were sometimes counter-productive for these men, leading to even slower reaction times for global targets. This may be the result of greater distractor interference, to which older adults are more vulnerable, and to which this sub-group of older men may have been especially susceptible.

Example of a Navon figure:

FFFFFF
F
FFFFFF
F
FFFFFF

Reference: 

Source: 

Topics: 

tags memworks: 

tags problems: 

Folic acid tied to better grades in Swedish teens

August, 2011

More evidence of the importance of adequate folate consumption for cognitive functioning at all ages.

Most research into the importance of folate and B12 levels has centered on seniors, and it does seem clear now that having adequate levels of these vitamins is important for maintaining cognitive functioning as you get older. Folic acid levels are of course also regarded as crucial when the brain is developing, which is why pregnant women are urged to take supplements, and why some countries fortify their bread with it. There is less research in the extensive ground between these two end-points.

A Swedish study involving 386 15-year-olds has now found that those in the top third of folic acid intake (more than 253 micrograms per day for girls and 335 for boys) performed significantly better on their school grades compared to those in the bottom third (less than 173 micrograms folic acid per day for girls and 227 for boys).

Interestingly, while homocysteine levels in the blood were initially significant, this association disappeared after other significant predictors (gender, smoking, and SES) were controlled for. Neither was a genotype linked to higher homocysteine levels (MTHFR 677 TT homozygosity) significantly related to academic achievement. Low folate and B12 levels are associated with higher homocysteine levels in the blood, and there is evidence that it is this increase in homocysteine that is the reason for the cognitive impairment seen in age-related cognitive decline. This finding, then, suggests that this is only one part of the story.

Sweden does not fortify flour with folic acid as the United States, Canada and Australia do. Folate is a B vitamin found particularly in citrus fruit, green leafy vegetables, whole-wheat bread, and dried beans and peas; however, they are often destroyed by cooking or processing.

The sum of school grades in 10 core subjects obtained in the final semester of compulsory 9 years of schooling was used as the measure of academic achievement

Reference: 

Source: 

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Alcohol's possible benefits for the brain

There seems to be quite a lot of evidence now, that a moderate amount of alcohol consumption (around 1-2 drinks a day) can help protect against Alzheimer’s — though not, a review concluded, vascular dementia or age-related cognitive decline (but the jury’s still out on that one, I think). Moderate alcohol consumption is significantly associated with other factors that help protect against dementia, such as better education, not living alone, and absence of depression, but seems to have an effect on its own account as well.

It must be emphasized that this positive effect is restricted to the ‘right’ level of alcohol consumption. The damage alcohol can do to the brain is only too well established.

The effect doesn’t appear to be restricted to a particular type of alcohol. Having said that, there are components in wine, especially red wine, that have also been associated with lower dementia risk. These components include polyphenols such as epicatechin, catechin and resveratrol.

Benefits may not apply to everyone however. One study found that carriers of the Alzheimer’s gene, APOe4, were more likely to develop dementia if they drank any alcohol — it was only non-carriers that showed a benefit of moderate drinking. Another large study found that the benefits of moderate drinking only applied to those who had no cognitive impairment. For those with mild cognitive impairment, drinking speeded up the rate of decline. Another, large long-running, study found that, although non-smokers who consumed moderate amounts of alcohol were less likely to have a stroke than non-drinkers, this didn’t apply to smokers.

These individual variations may explain the inconsistency in previous studies regarding the relationship between light to moderate drinking and age-related cognitive impairment.

The story of alcohol and the brain is clearly a complex one, not easily disentangled. One large, long-running study, for example, found an association between alcohol and brain atrophy even at moderate levels of consumption.

Older news items (pre-2010) brought over from the old website

Regular moderate alcohol intake has cognitive benefits in older adults

A six-year study involving over 3,000 seniors (75+) has found that for those who had no cognitive impairment at the start of the study, moderate drinking (1-2 drinks a day) was associated with a 37% reduction in risk of developing dementia compared to individuals who did not drink at all. The type of alcohol didn’t matter. However, for those who started the study with mild cognitive impairment, any consumption of alcohol was associated with faster rates of cognitive decline. Moreover, heavy drinkers were almost twice as likely to develop dementia during the study. The results are consistent with previous studies of middle-aged adults that suggest mild to moderate alcohol intake may reduce the risk of dementia, except in the case of individuals who already have mild to moderate cognitive impairment.

Sink, K.M. et al. 2009. Moderate alcohol intake is associated with lower dementia incidence: results from the Ginkgo Evaluation of Memory Study (GEMS). Presented at the Alzheimer's Association International Conference on Alzheimer's Disease July 11-16 in Vienna.

http://www.eurekalert.org/pub_releases/2009-07/wfub-rma071309.php

Moderate drinking can reduce risks of Alzheimer's dementia and cognitive decline

A review of 44 studies has concluded that moderate drinkers often have lower risks of Alzheimer's disease and other cognitive loss. Moderate alcohol consumption generally is defined as 1 drink or less per day for women and 1-2 drinks or less per day for men.

[2374] Collins, M. A., Neafsey E. J., Mukamal K. J., Gray M. O., Parks D. A., Das D. K., et al.
(2009).  Alcohol in Moderation, Cardioprotection, and Neuroprotection: Epidemiological Considerations and Mechanistic Studies.
Alcoholism: Clinical and Experimental Research. 33(2), 206 - 219.

http://www.eurekalert.org/pub_releases/2008-12/luhs-mdc122908.php

Chocolate, wine and tea improve brain performance

A study of over 2000 older Norwegians (aged 70-74) has found that those who consumed chocolate, wine, or tea had significantly better cognitive performance and lower risk of poor cognitive performance than those who did not. Those who consumed all 3 studied items had the best performance and the lowest risks for poor test performance. The associations between intake of these foodstuffs and cognition were dose dependent, with maximum effect at intakes of around 10 grams a day for chocolate and around 75–100 ml a day for wine, but approximately linear for tea. The effect was most pronounced for wine and modestly weaker for chocolate intake. The finding is consistent with research indicating that those who consume lots of flavonoids have a lower incidence of dementia.

[623] Nurk, E., Refsum H., Drevon C. A., Tell G. S., Nygaard H. A., Engedal K., et al.
(2009).  Intake of flavonoid-rich wine, tea, and chocolate by elderly men and women is associated with better cognitive test performance.
The Journal of Nutrition. 139(1), 120 - 127.

http://www.physorg.com/news149185135.html

Red grape seeds may help prevent Alzheimer's disease

Research into the nearly 5000 compounds contained in red wine to reveal the source of the health benefits seen from red wine has revealed that polyphenols derived from red grape seeds may be useful agents to prevent or treat Alzheimer's disease. Red grape seeds currently being developed with the name of Meganatural AZ were found to significantly reduce cognitive deterioration in genetically engineered mice, by preventing the formation of amyloid beta. The mice were given the extract before the age at which they normally develop signs of disease, suggesting the extract may help prevent or postpone the development of Alzheimer’s. The major polyphenol components in the grape seed extract product are catechin and epicatechin, which are also abundant in tea and cocoa. Unlike the polyphenol resveratrol, which has been shown to have similar effects, but requires extremely high doses, the catechins appear to be effective at much lower doses. Further research will of course be needed before human recommendations can be made.

[2377] Wang, J., Ho L., Zhao W., Ono K., Rosensweig C., Chen L., et al.
(2008).  Grape-Derived Polyphenolics Prevent Aβ Oligomerization and Attenuate Cognitive Deterioration in a Mouse Model of Alzheimer's Disease.
The Journal of Neuroscience. 28(25), 6388 - 6392.

http://www.eurekalert.org/pub_releases/2008-06/tmsh-pnr061708.php
http://www.eurekalert.org/pub_releases/2008-06/sfn-sig061708.php

Why moderate drinking may boost memory

Another study has come out suggesting moderate amounts of alcohol are good for the brain, and explaining why. The rat study found that low levels of alcohol increased the expression of a particular receptor, NR1, on the surface of neurons in the hippocampus. Increasing the number of NR1 receptors in a different group of rats resulted in a memory boost similar to that seen in the rats given low doses of alcohol. There were no toxic effects of low-level alcohol consumption (1—2 drinks a day) on the brain, but a higher dose of alcohol did damage neurons.

The findings were presented at the Society for Neuroscience's annual meeting on October 14-18 in Atlanta, Georgia.

http://www.sciencedaily.com/releases/2006/10/061025171322.htm
http://www.eurekalert.org/pub_releases/2006-10/osu-mdm102506.php

Cabernet sauvignon red wine reduces the risk of Alzheimer's disease

A mouse study has found moderate consumption of the red wine Cabernet Sauvignon significantly reduced Alzheimer’s-type deterioration of spatial memory function. The Cabernet Sauvignon used contained a very low content of resveratrol, 10-fold lower than the minimal effective concentration shown to promote Aß clearance in vitro. It is suggested that, instead, the benefit occurred through promoting non-amyloidogenic processing of amyloid precursor protein. The finding supports epidemiological evidence indicating that moderate wine consumption (one drink per day for women and two for men) may help reduce the relative risk for Alzheimer’s.

[2378] Wang, J., Ho L., Zhao Z., Seror I., Humala N., Dickstein D. L., et al.
(2006).  Moderate consumption of Cabernet Sauvignon attenuates Aß neuropathology in a mouse model of Alzheimer’s disease.
The FASEB Journal. 20(13), 2313 - 2320.

http://www.eurekalert.org/pub_releases/2006-09/tmsh-csr091806.php

Moderate alcohol intake associated with better mental function in older women

A study of over 7,000 older women (65-80) found that those who drink a moderate amount of alcohol have slightly higher levels of mental function than non-drinkers, particularly in verbal abilities. The researcher warned that "Until we better understand the reasons why alcohol consumption is associated with better cognitive functioning, these results on their own are not a reason for people who don't drink to start or for those who drink to increase their intake."

[455] Espeland, M. A., Coker L. H., Wallace R., Rapp S. R., Resnick S. M., Limacher M., et al.
(2006).  Association between alcohol intake and domain-specific cognitive function in older women.
Neuroepidemiology. 27(1), 1 - 12.

http://www.eurekalert.org/pub_releases/2006-05/wfub-mai053106.php

More support for benefits of some alcohol

A longitudinal study of an elderly community sample found that, over an average of 7 years, mild-to-moderate drinking was associated with less average decline in cognitive function compared to not drinking.

[1203] Ganguli, M., Bilt V. J., Saxton J. A., Shen C., & Dodge H. H.
(2005).  Alcohol consumption and cognitive function in late life: A longitudinal community study.
Neurology. 65(8), 1210 - 1217.

http://www.neurology.org/cgi/content/abstract/65/8/1210

Moderate alcohol intake may reduce cognitive decline in older women

Two recent large-scale epidemiological studies have come out recently with similar findings. Data from the Women's Health Initiative Memory Study (involving 4,461 women aged 65 to 79 years) has revealed that women who reported having one or more alcohol drinks daily had a 40% lower risk of significant declines in cognitive function over time, compared to women who reported no alcohol intake. It is possible that moderate alcohol intake may reduce the risk for narrowed vessels in the brain. In addition, alcohol may decrease the formation of plaque that is associated with Alzheimer's disease.
Data from the Nurses' Health Study, begun in 1976 and involving 12,480 women, now aged between 70 and 81 years old, has found that women who had the equivalent of one drink a day had a 23% lower risk of becoming mentally impaired during a two-year period, compared with non-drinkers. It made no significant difference whether they drank beer or wine.

[1108] Espeland, M. A., Gu L., Masaki K. H., Langer R. D., Coker L. H., Stefanick M. L., et al.
(2005).  Association between Reported Alcohol Intake and Cognition: Results from the Women's Health Initiative Memory Study.
Am. J. Epidemiol.. 161(3), 228 - 238.

[1115] Stampfer, M. J., Kang J H., Chen J., Cherry R., & Grodstein F.
(2005).  Effects of Moderate Alcohol Consumption on Cognitive Function in Women.
N Engl J Med. 352(3), 245 - 253.

http://www.eurekalert.org/pub_releases/2005-01/wfub-mai012105.php (1st study)
http://www.nature.com/news/2005/050117/full/050117-10.html (2nd study)

Drinking too much alcohol, and not enough, increases risk of cognitive impairment

In Finland, researchers re-examined 1018 participants from a study of 1464 men and women aged 65-79 studied in 1972 or 1977. They found that participants who drank no alcohol in midlife as well as those who drank alcohol frequently were twice as likely to have mild cognitive impairment in old age compared to those who drank alcohol infrequently. The effect of alcohol was however modified by the presence of the apolipoprotein e4 allele (implicated in dementia risk). People who were carriers of the apolipoprotein e4 allele had an increased risk of dementia with increasing alcohol consumption, with carriers of the gene significantly reducing their risk by never drinking.

[731] Kivipelto, M., Anttila T., Helkala E-L., Viitanen M., Kareholt I., Fratiglioni L., et al.
(2004).  Alcohol drinking in middle age and subsequent risk of mild cognitive impairment and dementia in old age: a prospective population based study.
BMJ. 329(7465), 539 - 539.

Possible benefits of alcohol in reducing cognitive decline

Another report from the Whitehall Study database. This one adds to the, still controversial, research linking moderate wine consumption with health and longevity. Of those who reported drinking alcohol in the past year, those who consumed at least one drink in the past week were significantly less likely to have poor cognitive function than those who did not. These benefits appeared even at levels of alcohol consumption that most sensible observers would consider excessive, and emphasizes once again that correlation is not causation. It seems likely that this association at least partly reflects other factors, and indeed, the correlation was reduced when social position was taken account of. It may also reflect the possible effect of alcohol in reducing risk of cardiovascular disease.

http://www.telegraph.co.uk/news/uknews/4193134/Alcohol-sharpens-your-brain-say-researchers.html

Alcohol's benefits for cognition may be overstated

Some studies (that receive a lot of media attention) have suggested that moderate alcohol drinking may have beneficial effects on the heart or the brain. Other studies have found no effect, or a negative one. Now a new study may provide an answer to the conflicting results. Using data from the Wisconsin Longitudinal Study, which has followed more than 10,000 men and women who graduated from Wisconsin high schools in 1957, researchers in 1992 asked the participants about their drinking habits. It was found that men who consumed low levels of alcohol in 1992 had higher scores on the abstract reasoning test than those who drank either more or less. However, when earlier cognitive ability (measured in high school) was taken into account, the difference between non-drinkers and those who had one drink a day disappeared. With the women, both non-drinkers and heavy drinkers had lower scores at age 53 than moderate drinkers. But when adolescent cognitive ability was taken into account, these differences disappeared. Participants will be re-examined next year, when they’re about 65.

[2375] Krahn, D., Freese J., Hauser R., Barry K., & Goodman B.
(2003).  Alcohol Use and Cognition at Mid‐Life: The Importance of Adjusting for Baseline Cognitive Ability and Educational Attainment.
Alcoholism: Clinical and Experimental Research. 27(7), 1162 - 1166.

http://www.eurekalert.org/pub_releases/2003-08/cfta-abo082103.htm

Drinking wine may lower risk of dementia

Researchers in Copenhagen have followed up an analysis of drinking patterns for wine, beer and liquor of 1,709 people in the 1970s with an assessment of dementia in the 1990s, when participants were age 65 or older. 83 of the participants had developed dementia. Their alcohol intake was compared to that of those who did not develop dementia. It was found that those who drank wine occasionally had a lower risk of developing dementia, including Alzheimer's disease. Those who drank wine every day were no more or less likely to develop dementia than those who drank it less often. The study also found that occasional beer drinking was associated with an increased risk of developing dementia. It is important to note that eating habits were not investigated, and research suggests that wine drinkers may have better dietary habits than beer and liquor drinkers.

[2376] Truelsen, T., Thudium D., & Grønbæk M.
(2002).  Amount and type of alcohol and risk of dementia.
Neurology. 59(9), 1313 - 1319.

http://www.eurekalert.org/pub_releases/2002-11/aaon-dwm110702.php

Moderate alcohol consumption may help prevent dementia

Recent research has suggested that moderate alcohol consumption may have positive health benefits for cardiovascular and cerebrovascular functioning. Given the connection between dementia in old age and cerebrovascular disease, a recent Italian study analyzed data from 15,807 patients (65 years of age or older) to assess whether there is any link between alcohol consumption and cognitive function. Signs of cognitive derangement were found in 19% of the participants who reported regular alcohol consumption, and in 29% of those who abstained from alcohol. The quantity of daily alcohol consumption was an important factor. The risk of cognitive impairment was reduced among women whose daily alcohol consumption was less than 40 grams and among men who drank less than 80 grams. Higher levels of alcohol consumption showed an increased risk of cognitive impairment when compared with both abstainers and moderate drinkers.

[954] Zuccalà, G., Onder G., Pedone C., Cesari M., Landi F., Bernabei R., et al.
(2001).  Dose-Related Impact of Alcohol Consumption on Cognitive Function in Advanced Age: Results of a Multicenter Survey.
Alcoholism: Clinical and Experimental Research. 25(12), 1743 - 1748.

http://www.eurekalert.org/pub_releases/2001-12/ace-aad121001.php

A Dutch study suggests that light-to-moderate alcohol consumption could reduce the risk of dementia among older people. Light-to-moderate alcohol consumption (1 to 3 drinks per day) was associated with a 42% risk reduction of all dementia, and around a 70% reduction in risk of vascular dementia.

[794] Ruitenberg, A., van Swieten J. C., Witteman J CM., Mehta K. M., van Duijn C. M., Hofman A., et al.
(2002).  Alcohol consumption and risk of dementia: the Rotterdam Study.
The Lancet. 359(9303), 281 - 286.

tags development: 

tags lifestyle: 

tags problems: 

Estrogen & Hormone therapy

Estrogen's effect on the brain is a complex story, one which we are only beginning to understand. We know it's important for women, but we're not sure about the details. One of the problems is that it appears to interact with stress. There are two aspects to estrogen's effects on women: normal monthly fluctuations in estrogen levels, and menopause.

It's also important to distinguish post-menopause (once you have completely stopped menstruating) from perimenopause (the years of menstrual irregularity leading up to this).

In general, the last few years of research seem to be coming to the conclusion that any cognitive problems women experience as they approach menopause is limited, both in time and in task, and depends in part on other factors. For example, those who experience many hot flashes may have poorer verbal memory, but the main cause for this may be the poorer sleep quality; those who are distressed or experience mood changes may find their memory and concentration affected for that reason.  These findings suggest the best approach to dealing with cognitive problems in perimenopause is to tackle the physical and/or emotional causes.

Post-menopause is different. Post-menopause is all about low estrogen levels, and the importance of estrogen for brain function. Nevertheless, estrogen therapy for postmenopausal women has had inconsistent results; there has even been some research suggesting it may increase the risk of later dementia. There is also some suggestion that it may not help those women who have cognitively stimulating environments, or are highly educated. And other indications that timing might be critical -- the age at which you begin hormone therapy. At the moment, we simply have too little clear evidence to warrant recommending hormone therapy for cognitive reasons (particularly in light of the possible cancer risk), or to know when it might be effective.

Excitingly, however (because there is no downside!), there is some evidence that physical exercise can counter the cognitive decline postmenopausal women may experience. There's also a study suggesting that the effect of low estrogen after menopause is not to impair cognition but simply to change it -- however, because women aren't prepared for, or understand, these changes, they perceive it as impairment. That would suggest that what is needed is an education program in how the brain changes (but first we have to understand exactly how it does change!).

Older news items (pre-2010) brought over from the old website

How does estrogen affect cognition?

Estrogen levels affect hippocampal wiring

Many studies have established the role of estrogen in female cognition. A rat study has now revealed the reason. It appears that the "wiring" in the hippocampus expands and retracts in relation to the amount of estrogen present during the estrous/menstrual cycle. The findings also suggest that “the brain's capacity for growth is well beyond anything we considered in the past”.
Routtenberg, A. 2005. Presented at the Society for Neuroscience's 35th Annual Meeting in Washington, D.C.
http://www.eurekalert.org/pub_releases/2005-11/nu-bma111405.php

How estrogen affects the brain

A new study involved cultured rat neurons has revealed how estrogen affects learning and memory. It appears that, in females, estrogen can activate particular glutamate receptors within the hippocampus. Glutamate is the primary excitatory neurotransmitter in the brain, allowing for fast communication between neurons.
[271] Boulware, M. I., Weick J. P., Becklund B. R., Kuo S. P., Groth R. D., & Mermelstein P. G.
(2005).  Estradiol Activates Group I and II Metabotropic Glutamate Receptor Signaling, Leading to Opposing Influences on cAMP Response Element-Binding Protein.
J. Neurosci.. 25(20), 5066 - 5078.
http://www.eurekalert.org/pub_releases/2005-05/uom-uom051905.php

Estrogen effect on memory influenced by stress

The question of whether estrogen helps memory and cognition in women has proven surprisingly difficult to answer, with studies giving conflicting results. Now it seems the answer to that confusion is: it depends. And one of the things it depends on may be the level of stress the woman is experiencing. A rat study has found that the performance of female rats in a water maze was affected by the interaction of hormone level (whether the rat was estrous or proestrous) with water temperature (a source of physical stress). Those rats with high hormone levels did better when the water was warm, while those with low hormone levels did better when the water was cold. The researchers suggest both timing and duration of stress might be factors in determining the effect of hormones on cognition.
[384] Rubinow, M. J., Arseneau L. M., Beverly L. J., & Juraska J. M.
(2004).  Effect of the Estrous Cycle on Water Maze Acquisition Depends on the Temperature of the Water..
Behavioral Neuroscience. 118(4), 863 - 868.
http://www.eurekalert.org/pub_releases/2004-08/uoia-sss082704.php

Estrogen combines with stress to impair memory

A rat study has found that male and female rats performed equally well on a task involving the prefrontal cortex when under no stress, and when highly stressed, both made significant memory errors. But importantly, after exposure to a moderate level of stress, females were impaired, but males were not. When investigated further, it was found that female rats only showed this sensitivity when they were in a high-estrogen phase of their estrus cycle. The estrogen effect was confirmed in a further study using female rats who had had their ovaries removed, thus enabling the researchers to compare the effects of estrogen versus a placebo. These results suggest that high levels of estrogen can act to enhance the stress response, causing greater stress-related cognitive impairments, while providing reassurance that estrogen appears to have no effect on cognitive performance under non-stressful conditions.
[746] Shansky, R. M., Glavis-Bloom C., Lerman D., McRae P., Benson C., Miller K., et al.
(2003).  Estrogen mediates sex differences in stress-induced prefrontal cortex dysfunction.
Mol Psychiatry. 9(5), 531 - 538.
http://www.eurekalert.org/pub_releases/2003-12/mp-epg112603.php

Why estrogen helps memory

Estrogen has been implicated as having a role in memory in a number of studies, although findings have been mixed as to the value of HRT for improving memory in post-menopausal women. A new study helps us understand why estrogen might be helpful. The study details how nerve cells in the hippocampus "grow in complexity" when exposed to estrogen, increasing connections among the nerve cells. It may be that, without estrogen, the connections that are there might not work as efficiently in storing and recalling certain types of memories. Previous studies have shown that the ability of women to remember word lists varies during their normal monthly cycle.
[1005] Akama, K. T., & McEwen B. S.
(2003).  Estrogen Stimulates Postsynaptic Density-95 Rapid Protein Synthesis via the Akt/Protein Kinase B Pathway.
J. Neurosci.. 23(6), 2333 - 2339.
[880] Znamensky, V., Akama K. T., McEwen B. S., & Milner T. A.
(2003).  Estrogen Levels Regulate the Subcellular Distribution of Phosphorylated Akt in Hippocampal CA1 Dendrites.
J. Neurosci.. 23(6), 2340 - 2347.
http://www.eurekalert.org/pub_releases/2003-03/ru-rwc031403.php

Estrogen may dictate the problem-solving strategy chosen

Several studies have suggested estrogen may be beneficial for cognitive functioning in women. New research using rats suggests estrogen may be very specific in what types of learning it helps - and what types it may impair. In rats, it appeared to enhance place-learning, at the expense of response learning. It is suggested that postmenopausal women may experience a shift into a problem-solving mode more common to men. "Women may actually get better at performing a task from a different approach, but they are not used to doing it that way, so they view the change as an impairment."
[831] Korol, D. L., & Kolo L. L.
(2002).  Estrogen-induced changes in place and response learning in young adult female rats..
Behavioral Neuroscience. 116(3), 411 - 420.
http://www.eurekalert.org/pub_releases/2002-05/uoia-emd051502.php

Are you likely to develop cognitive problems in menopause?

Menopause transition may cause trouble learning

A four-year study of over 2,300 women, aged 42 to 52, has found evidence suggesting that during the early and late perimenopause women do not learn as well as they do during other menopause transition stages. Processing speed improved with repeated testing during premenopause, early perimenopause (menstrual irregularity but no "gaps" of 3 months), and postmenopause (no period for 12 months), but scores during late perimenopause (no period for three to 11 months) did not show the same degree of improvement. Improvements in processing speed were considerably reduced in late perimenopause, and improvement in verbal memory performance was reduced during both early and late perimenopause (and indeed almost non-existent during late perimenopause). These findings are consistent with self-reported memory difficulties — 60% of women state that they have memory problems during the menopause transition. The good news is that the effect seems to be temporary. Interestingly, although taking estrogen or progesterone hormones before menopause helped verbal memory and processing speed, taking them after the final period had a negative effect. This is consistent with other research indicating that the timing of hormone therapy is crucial to its effects.
[554] Greendale, G. A., Huang M. - H., Wight R. G., Seeman T., Luetters C., Avis N. E., et al.
(2009).  Effects of the menopause transition and hormone use on cognitive performance in midlife women.
Neurology. 72(21), 1850 - 1857.
http://www.eurekalert.org/pub_releases/2009-05/aaon-mtm051909.php

Hot flashes underreported and linked to forgetfulness

In the first study to explore the relationship between objectively measured hot flashes in menopausal women and memory performance, it’s been found that women dramatically underreport the number of hot flashes they experience (by about 43%), and that, with a clear measure of hot flashes, an association between number of hot flashes and poor verbal memory is evident. There was no relationship between the number of hot flashes women thought they had and memory performance. The average number of objective hot flashes was 19.5 per day. Unsurprisingly, poor sleep also predicted poorer memory, but it was also affected by the number of hot flashes during the night when a woman was sleeping. The researchers recommend treating women for their vasomotor symptoms.
An extended interview as MP3 audio file is at https://blackboard.uic.edu/bbcswebdav/institution/web/news/podcasts/PdCs...
[1128] Maki, P. M., Drogos L. L., Rubin L. H., Banuvar S., Shulman L. P., & Geller S. E.
(2008).  Objective hot flashes are negatively related to verbal memory performance in midlife women.
Menopause (New York, N.Y.). 15(5), 848 - 856.
http://www.eurekalert.org/pub_releases/2008-06/uoia-hfu061608.php

Memory problems at menopause

Findings from a study of 24 women approaching menopause have confirmed an earlier study involving over 800 women that found such women are no more likely than anyone else to suffer from memory retrieval problems. However, they did find that the women who complained more about problems with forgetfulness had a harder time learning or "encoding" new information, although they didn’t have actually have an impaired ability to learn new information. Although a larger study is needed to explore this link in more detail, the researchers suggest that stress and emotional upheaval may be responsible for attention failures that mean information isn’t encoded. The researchers did find that most of the women in their study had some sort of mood distress, including symptoms of depression or anxiety (note that this was not a random group, but women who were worried about their memory).
The study was reported at the annual meeting of the International Neuropsychological Society in Boston.
http://www.eurekalert.org/pub_releases/2006-02/uorm-mpa020206.php

Since 1996, 803 African American and white women aged 40 to 55 have been tested annually for loss of brain function. Performance was compared annually for women in premenopausal, during menopause, and postmenopausal groups. Small but significant increases in performance were found over time during the premenopausal and perimenopausal phases, leading the authors to conclude that transition through menopause is not accompanied by a decline in working memory and perceptual speed.
[1201] Meyer, P. M., Powell L. H., Wilson R. S., Everson-Rose S. A., Kravitz H. M., Luborsky J. L., et al.
(2003).  A population-based longitudinal study of cognitive functioning in the menopausal transition.
Neurology. 61(6), 801 - 806.
http://www.eurekalert.org/pub_releases/2003-09/aa-nss091803.php

Does estrogen help cognition?

For:

Hormone replacement therapy may improve visual memory of postmenopausal women
A study of 10 postmenopausal women (aged 50-60) found that those taking combined estrogen-progestin hormone therapy for four weeks showed significantly increased activity in the prefrontal cortex when engaged in a visual matching task, compared with those on placebo.
[1409] Smith, Y. R., Love T., Persad C. C., Tkaczyk A., Nichols T. E., & Zubieta J-K.
(2006).  Impact of combined estradiol and norethindrone therapy on visuospatial working memory assessed by functional magnetic resonance imaging.
The Journal of Clinical Endocrinology and Metabolism. 91(11), 4476 - 4481.
http://www.eurekalert.org/pub_releases/2006-11/uomh-hrt111606.php

Estrogen improves verbal memory in postmenopausal women

A study involving 60 postmenopausal women aged 32.8 to 64.9, found those receiving daily estrogen treatment (conjugated equine estrogens — Premarin) showed improved oral reading and verbal memory performance, compared to those receiving a placebo. This is consistent with brain imaging date indicating estrogen produces brain activations in the inferior parietal lobule, a region sensitive to phonological demands and implicated in reading.
[374] Shaywitz, S. E., Naftolin F., Zelterman D., Marchione K. E., Holahan J. M., Palter S. F., et al.
(2003).  Better oral reading and short-term memory in midlife, postmenopausal women taking estrogen.
Menopause (New York, N.Y.). 10(5), 420 - 426.
http://www.eurekalert.org/pub_releases/2003-09/yu-eis092303.php

Hormone replacement therapy may have cognitive benefits for older women

A study of more than 2,000 women 65 or older, found that those who underwent hormone replacement therapy after menopause appeared to enjoy better mental functioning. Women 85 and older did especially well. The improvements were seen only in women free from dementia. However, the sample does not reflect the general population - most of the participants were Mormon, and the prohibition of alcohol and tobacco might be a significant factor.
[213] Carlson, M. C., Zandi P. P., Plassman B. L., Tschanz JA. T., Welsh-Bohmer K. A., Steffens D. C., et al.
(2001).  Hormone replacement therapy and reduced cognitive decline in older women: The Cache County Study.
Neurology. 57(12), 2210 - 2216.
http://tinyurl.com/i87m

The positive effects of estrogen on memory

Postmenopausal women who take estrogen and young college-aged women performed more consistently on memory tests compared with postmenopausal women not taking the hormone. Consistency differs from overall memory ability and is a relatively new area in research about the neuropsychology of aging. Consistency measures memory capability on multiple administrations of the same test or on several related tests in a short period of time.
The study involved 48 postmenopausal women (aged 60 - 80), and 16 younger women (18 - 30). The older women were divided into three groups: 16 non-hormone users, 16 estrogen-users and 16 estrogen and progesterone-users. Younger women and older women taking estrogen performed more consistently than the older women not taking the hormone, as well as having higher overall memory scores. Women taking a combination of estrogen and progesterone did not perform as consistently as the estrogen-only users. This finding suggests progesterone may block some of the beneficial effects of taking estrogen alone.
Wegesin, D.J., Friedman, D., Varughese, N. & Stern, Y. 2001. Effects of estrogen-use and aging on intraindividual variability in recognition memory. Paper presented to the annual Society for Neuroscience meeting in San Diego, US.
http://www.eurekalert.org/pub_releases/2001-11/cuco-ssp111501.php

Against:

Combined hormone therapy doesn't boost memory

A study of 180 recently menopausal women found no effect of hormone therapy (a combination of estrogen and progesterone) on cognitive function. Previous research has indicated a positive benefit of estrogen on cognition, so it is speculated that progestin may counteract these positive effects.

[917] Maki, P. M., Gast M. J., Vieweg A. J., Burriss S. W., & Yaffe K.
(2007).  Hormone therapy in menopausal women with cognitive complaints: A randomized, double-blind trial.
Neurology. 69(13), 1322 - 1330.

http://www.eurekalert.org/pub_releases/2007-09/aaon-hti091807.php

Removing ovaries before menopause increases risk of cognitive impairment

A very long-running study of some 1,500 women who underwent the removal of one or both ovaries for non-cancer-related reasons, has found that women who had one or both ovaries removed before menopause were nearly two times more likely to develop cognitive problems or dementia compared to women who did not have the surgery. In addition, those women who were younger when their ovaries were removed were more likely to develop dementia than women who were older when their ovaries were removed. This finding adds to other research suggesting that there may be a critical age window for the protective effect of estrogen on the brain in women.

[1291] Rocca, W. A., Bower J. H., Maraganore D. M., Ahlskog J. E., Grossardt B. R., de Andrade M., et al.
(2007).  Increased risk of cognitive impairment or dementia in women who underwent oophorectomy before menopause.
Neurology. 69(11), 1074 - 1083.

http://www.eurekalert.org/pub_releases/2007-08/aaon-rob082107.php

Estrogen-alone hormone therapy could increase risk of dementia in older women

A new report from the Women's Health Initiative Memory Study suggests that older women using estrogen-alone hormone therapy could be at a slightly greater risk of developing dementia, including Alzheimer's disease (AD), than women who do not use any menopausal hormone therapy. Among 10,000 women using conjugated equine estrogens, 37 could be expected to develop dementia, compared to 25 in 10,000 women using the placebo. Previous reports from the Study found a greater risk with hormone therapy involving both estrogen plus progestin: among 10,000 women over age 65 using estrogen plus progestin there might be 45 cases of dementia compared to 22 cases in 10,000 older women on placebo.
It was also reported that beginning estrogen-alone hormone therapy after age 65 can have a small negative effect on overall cognitive abilities and that this negative effect may be greater in women with existing cognitive problems.
[871] Lewis, C. E., Masaki K., Coker L. H., for the Women's Health Initiative Memory Study, Shumaker S. A., Legault C., et al.
(2004).  Conjugated Equine Estrogens and Incidence of Probable Dementia and Mild Cognitive Impairment in Postmenopausal Women: Women's Health Initiative Memory Study.
JAMA. 291(24), 2947 - 2958.
[1309] Hays, J., Johnson K. C., Coker L. H., Dailey M., Bowen D., Rapp S. R., et al.
(2003).  Effect of Estrogen Plus Progestin on Global Cognitive Function in Postmenopausal Women: The Women's Health Initiative Memory Study: A Randomized Controlled Trial.
JAMA. 289(20), 2663 - 2672.
http://www.eurekalert.org/pub_releases/2004-06/nioa-eht062204.php
http://www.eurekalert.org/pub_releases/2004-06/wfub-etd061704.php

For women over 65, Combined Hormone Therapy increases risk of dementia

Much to the researchers’ surprise and disappointment, a four-year experiment involving 4,532 women at 39 medical centers, has found that combined hormone therapy (involving both estrogen and progestin) doubles the risk of Alzheimer's disease and other types of dementia in women who began the treatment at age 65 or older, although the risk is still small : for every 10,000 women 65 and older who take hormones, 23 of the predicted 45 cases of dementia a year, will be attributable to the hormones. The study also found that the combined hormone therapy produced no improvement in general cognitive function, and in fact had adverse effects on cognition among some women. This supports an earlier study suggesting that, while estrogen is helpful to cognitive function in postmenopausal women, the benefits can be cancelled out by progestin / progesterone. The study also confirmed previous research showing that the combination therapy increased the risk of stroke - previous research has indicated that risk factors for stroke are also risk factors for cognitive decline.
[918] Jackson, R. D., Morley Kotchen J., Wassertheil-Smoller S., Wactawski-Wende J., Shumaker S. A., Legault C., et al.
(2003).  Estrogen Plus Progestin and the Incidence of Dementia and Mild Cognitive Impairment in Postmenopausal Women: The Women's Health Initiative Memory Study: A Randomized Controlled Trial.
JAMA. 289(20), 2651 - 2662.
[1309] Hays, J., Johnson K. C., Coker L. H., Dailey M., Bowen D., Rapp S. R., et al.
(2003).  Effect of Estrogen Plus Progestin on Global Cognitive Function in Postmenopausal Women: The Women's Health Initiative Memory Study: A Randomized Controlled Trial.
JAMA. 289(20), 2663 - 2672.
[1194] Rossouw, J. E., Aragaki A., Safford M., Stein E., Laowattana S., Mysiw J. W., et al.
(2003).  Effect of Estrogen Plus Progestin on Stroke in Postmenopausal Women: The Women's Health Initiative: A Randomized Trial.
JAMA. 289(20), 2673 - 2684.
http://www.eurekalert.org/pub_releases/2003-05/wfub-chr052203.php

When is estrogen therapy helpful?

Cognitive benefit of estrogen minimal for the highly educated?
A mouse study sheds light on the mixed results coming from investigations into the cognitive effects of hormone replacement therapy. The study found no beneficial effect of estrogen in female mice who were raised in a stimulating environment. On the other hand, mice raised in standard conditions showed significant spatial and object memory improvement when treated with a high dose of estrogen (following removal of their ovaries). Among mice not treated with estrogen, an enriched environment alone significantly improved spatial memory. These results might help to explain why studies of hormone replacement therapy do not show beneficial effects for all women. Most studies of HRT use very well-educated women.
[1229] GRESACK, J. E., & Frick K. M.
(2004).  ENVIRONMENTAL ENRICHMENT REDUCES THE MNEMONIC AND NEURAL BENEFITS OF ESTROGEN.
Neuroscience. 128(3), 459 - 471.
http://www.eurekalert.org/pub_releases/2004-10/yu-eos102204.php

New insights into hormone therapy highlight when estrogen best aids brain

Several studies have been exploring some of the many variables that may be important in determining the effect of hormone replacement therapy.
A mouse study compared the effects of receiving daily estrogen injections (“continuous treatment”) with the effects of receiving it every four days (“cyclical treatment”). The treatment lasted three months. Ovariectomized mice receiving the continuous treatment performed better on memory tasks than those receiving cyclical treatment.
Another mouse study compared the brains of ovariectomized mice treated with continuous estrogen for 47 days with those not so treated, and found that, after five days on estrogen, estrogen-treated mice produced more of the proteins important for neuron repair and neuronal function. However, with prolonged, continuous estrogen treatment, this effect diminished, and by day 47 the estrogen-treated mice were similar to the non-estrogen-treated mice in levels of the repair proteins. Mice that did not receive estrogen showed an elevation of a brain protein associated with the negative aspects of brain aging, while estrogen-treated mice did not.
A rat study examined the effects of progesterone (a component of many hormone therapies), and found that ovariectomized rats receiving progesterone exhibited deficiencies in learning and memory, supporting the hypothesis that progesterone negatively affects memory during aging. It’s suggested that the negative outcome of several studies evaluating combined estrogen/progesterone HT may be due, in part, to unfavorable effects of progesterone.
Other rat studies have found that two established protective actions of estrogen with relevance to Alzheimer's are negatively affected by the presence of progesterone.
Another study using neurons in culture demonstrated the importance of timing. Neurons exposed to estrogen prior to exposure to beta-amyloid (the protein implicated in Alzheimers) had a significantly greater rate of survival than those exposed to estrogen after being exposed to beta-amyloid. The results are consistent with clinical studies in which women who received estrogen hormone therapy at the time of menopause, before cognitive degeneration becomes apparent, have a lower risk of developing Alzheimer's disease than women who never receive any sort of HT, while for women in their 60s and 70s, hormone therapy may make things worse.
Papers presented at the 34th Society for Neuroscience annual meeting in San Diego in late October 2004.
http://www.eurekalert.org/pub_releases/2004-10/sfn-nii102604.php

Dangers of hormone therapy

Getting the benefits of estrogen without the downside

We know estrogen helps learning and memory, but estrogen therapy also increases cancer risk. That’s why the results of a mouse study are exciting. The study found that estrogen acts through calpain, a protein crucial to learning and memory, and like adrenalin (which acts like a hormone in most of the body but as a neurotransmitter in the brain), it does so as a neurotransmitter, modulating synaptic transmission. The findings suggest drugs that target calpain directly may provide the same cognitive benefits of estrogen therapy, without the medical risks.
[299] Zadran, S., Qin Q., Bi X., Zadran H., Kim Y., Foy M. R., et al.
(2009).  17-β-Estradiol increases neuronal excitability through MAP kinase-induced calpain activation.
Proceedings of the National Academy of Sciences. 106(51), 21936 - 21941.
http://www.eurekalert.org/pub_releases/2009-12/uosc-cot120809.php

Other aids to help memory in menopausal women

Less cognitive impairment seen in women taking raloxifene

Raloxifene modulates the activity of the hormone estrogen and is one of the most widely prescribed drugs for the treatment of osteoporosis. A 3-year worldwide clinical trial involving 7705 postmenopausal women with osteoporosis found that those taking 120mg of raloxifene had a 33% less chance of developing mild cognitive impairment. There was no cognitive benefit from a 60mg dose. Note that, of the 5386 women participating in the cognitive part of this trial, only 3.4% had mild cognitive impairment, and 1% had dementia.
[757] Yaffe, K., Krueger K., Cummings S. R., Blackwell T., Henderson V. W., Sarkar S., et al.
(2005).  Effect of Raloxifene on Prevention of Dementia and Cognitive Impairment in Older Women: The Multiple Outcomes of Raloxifene Evaluation (MORE) Randomized Trial.
Am J Psychiatry. 162(4), 683 - 690.
http://www.eurekalert.org/pub_releases/2005-04/uoc--lci040605.php

The estrogen drug raloxifene may help prevent cognitive decline in women over 70

The designer estrogen drug raloxifene has been prescribed to millions of postmenopausal women for osteoporosis, but its effects on the aging brain are unclear. A new study shows that although raloxifene does not affect the cognitive performance of most women, it may help prevent decline among women older than 70 and women whose cognitive performance is declining regardless of age.
Yaffe, K. et al. 2001. Cognitive Function in Postmenopausal Women Treated with Raloxifene. New England Journal of Medicine, 344, 1207-1213.Yaffe, K. et al. 2001. Cognitive Function in Postmenopausal Women Treated with Raloxifene. New England Journal of Medicine, 344, 1207-1213.
http://www.eurekalert.org/pub_releases/2001-04/UNKN-Derm-1704101.php

Fitness counteracts cognitive decline from hormone-replacement therapy

A study of 54 postmenopausal women (aged 58 to 80) suggests that being physically fit offsets cognitive declines attributed to long-term hormone-replacement therapy. It was found that gray matter in four regions (left and right prefrontal cortex, left parahippocampal gyrus and left subgenual cortex) was progressively reduced with longer hormone treatment, with the decline beginning after more than 10 years of treatment. Therapy shorter than 10 years was associated with increased tissue volume. Higher fitness scores were also associated with greater tissue volume. Those undergoing long-term hormone therapy had more modest declines in tissue loss if their fitness level was high. Higher fitness levels were also associated with greater prefrontal white matter regions and in the genu of the corpus callosum. The findings need to be replicated with a larger sample, but are in line with animal studies finding that estrogen and exercise have similar effects: both stimulate brain-derived neurotrophic factor.
[375] Erickson, K. I., Colcombe S. J., Elavsky S., McAuley E., Korol D. L., Scalf P. E., et al.
(2007).  Interactive effects of fitness and hormone treatment on brain health in postmenopausal women.
Neurobiology of Aging. 28(2), 179 - 185.
http://www.eurekalert.org/pub_releases/2006-01/uoia-fcc012406.php

tags development: 

tags lifestyle: 

tags problems: 

Alcohol's damage to the brain

While moderate drinking seems to have a protective effect against age-related cognitive decline and dementia, cognitive impairment produced by excess alcohol is only too evident. Here are a few less obvious cognitive effects:

Simulated laparoscopic surgery was impaired in both novices and experts on the day following an evening during which excessive alcohol was consumed, although experts were less impaired than novices. Performance had returned to baseline levels by 4:00 p.m.

When people drank before viewing a video of serious road traffic accidents, those given a smaller amount of alcohol experienced more flashbacks during the next week than those given a larger amount of alcohol, and those given no alcohol. Those who had large amounts of alcohol had poorer memories of the event. It’s suggested that alcohol impairs contextual memory first.

Another study found that recognition of different-race faces was unaffected by alcohol, but recognition of own-race faces was — meaning recognition of same-race faces was at about the same level of accuracy as different-race faces.

Cognitive impairment produced by excess alcohol is of course only too evident. Here are a few less obvious cognitive effects:

Simulated laparoscopic surgery was impaired in both novices and experts on the day following an evening during which excessive alcohol was consumed, although experts were less impaired than novices. Performance had returned to baseline levels by 4:00 p.m.

When people drank before viewing a video of serious road traffic accidents, those given a smaller amount of alcohol experienced more flashbacks during the next week than those given a larger amount of alcohol, and those given no alcohol. Those who had large amounts of alcohol had poorer memories of the event. It’s suggested that alcohol impairs contextual memory first.

Another study found that recognition of different-race faces was unaffected by alcohol, but recognition of own-race faces was — meaning recognition of same-race faces was at about the same level of accuracy as different-race faces.

Heavy drinking

Heavy drinking can be chronic, or occasional. Both have their price.

A rat study suggests that it doesn’t take all that long before heavy drinking produces long-lasting cognitive deficits. Rats drinking for eight weeks (but not four) developed deficits that lasted at least 12 weeks after drinking stopped — “equivalent to a human that drank six to eight beers or one bottle of wine a day every day for six years experiencing learning and memory deficits up to nine years after they stopped drinking alcohol."

Brain scans of heavy social drinkers have revealed damage to white matter that was associated with lower executive and working memory functions. This is consistent with a self-report study that found that heavy users of alcohol were more likely to miss appointments, forget birthdays and pay bills on time, and to forget whether they had done something or where they had put something.

One study suggests that heavy drinking is particularly a problem for those infected with HIV. The mediotemporal lobe is affected early in both these conditions, so it is not surprising that those positive for HIV with a history of chronic heavy drinking were found to have trouble encoding new information for long-term memory.

Smoking and alcohol

Smoking has a particularly negative effect in conjunction with alcohol (and unfortunately they are often found in tandem). While moderate drinking can in some circumstances have positive effects on the brain, this is probably not the case for those who smoke. Moreover, smoking makes it much harder for the brain to recover from the effects of alcohol abuse, the damage done to the brain by heavy alcohol consumption is likely to be much worse if the individual is a smoker.

Alcoholism

One of the characteristics of alcoholics is that they don’t recognize the extent of their problem. So perhaps it’s no surprise that a study found that alcoholics were relatively unaware of their memory deficits and believed that their memory was much better than it was. Moreover, the greater their deficits, the less they were aware of them!

Years of heavy alcohol consumption impair executive functions, including judgment, problem solving, decision making, planning, and social conduct.

Imaging studies indicate that the brains of alcoholics develop compensatory mechanisms to maintain cognitive skills despite alcohol's damages. It seems likely that this wider activity comes at the expense of other tasks, thus reducing their ability to multitask.

Excessive chronic drinking is also associated with deficits in comprehending emotional information, such as recognizing different facial expressions, and visuospatial deficits, characterized by difficulties completing tasks such as putting pieces of a puzzle together or map reading. While long-term abstinence can recover most of the cognitive function lost, spatial processing abilities seem much harder to recover.

In line with these problems of executive function, episodic and spatial memory, the prefrontal cortex and the hippocampus are especially vulnerable to the effects of chronic alcoholism.

Alcoholics have also been found to have an impaired cortisol response to stress, and this is associated with lower scores on measures of problem-solving ability and memory. Another exacerbating factor may come from poorer sleep — recovering alcoholics have been found to have significantly poorer sleep quality.

There is some evidence that women are more vulnerable to the effects of binge drinking and chronic heavy drinking.

Alcohol and the adolescent brain

Binge drinking is particularly evident among young people. Several studies point to effects on executive functions, including attention and working memory. This has consequences for planning and decision-making, as well as memory tasks.

Memory impairment following too much alcohol is particularly common among adolescent drinkers, possibly because of disruption in the hippocampus, which is still developing during adolescence.

Other physiological consequences of teenage binge drinking may be damaged white matter connectivity, and reduced activity of many neurotransmitter genes. There is some indication that some of these effects may persist into adulthood.

Prenatal exposure

Studies suggest that there is no safe dose, nor safe time to drink, for pregnant women, although the timing does affect the nature of the damage. It seems that alcohol is especially damaging for the development of the dopamine system.

Children prenatally exposed to alcohol are not consistently impaired however. A monkey study suggests why — it seems a gene variant makes the carrier more susceptible to the effects of fetal alcohol exposure. The gene has previously been implicated in increased depression risk.

Other research has suggested that children whose mothers are older than 30 years, those whose mothers have alcohol dependence, those whose parents provide a less stimulating environment, and those whose mothers reported drinking during the time of conception, are at greater risk from prenatal alcohol exposure.

It’s also the case that cognitive deficits are not always evident. One study found that children prenatally exposed to moderate-to-heavy levels of alcohol were perfectly competent at simple tasks, but failed when asked to multi-task. Such working memory deficits may partly be a result of slower processing speed.

Hope comes from a finding that two factors can considerably mitigate the negative effects of prenatal alcohol exposure: being diagnosed early in life and being raised in a stable and nurturing environment.

Children with fetal alcohol spectrum disorder are particularly impaired in mathematical ability, possibly due to specific deficits in memory for numbers and sequences.

Distinguishing Fetal Alcohol Spectrum Disorder from other developmental disorders may have got easier, with a simple test that measures eye movement.

Older news items (pre-2010) brought over from the old website

Alcoholism's effect on sleep persists

A study involving 42 long-term alcoholics who had not had a drink for up to 719 days (mean age 49 years, 27 men) has found that, compared to controls, alcoholics had significantly poorer sleep quality, measured by a significantly lower percentage of slow wave sleep and significantly more stage 1 non-rapid eye movement (NREM) sleep. Moreover, estimated lifetime alcohol consumption was significantly related to the scores on the Pittsburgh Sleep Quality Index, with higher lifetime consumption predicting less sleep satisfaction. The reduction in slow wave activity was specific to NREM sleep. This could act as an exacerbating factor in alcoholics' cognitive decline.

[792] Colrain, I. M., Turlington S., & Baker F. C. (2009).  Impact of alcoholism on sleep architecture and EEG power spectra in men and women. Sleep. 32(10), 1341 - 1352.

http://www.eurekalert.org/pub_releases/2009-10/aaos-aeo092309.php

Alcoholics show abnormal brain activity when processing facial expressions

Excessive chronic drinking is known to be associated with deficits in comprehending emotional information, such as recognizing different facial expressions. Now an imaging study of abstinent long-term alcoholics has found that they show decreased and abnormal activity in the amygdala and hippocampus when looking at facial expressions. They also show increased activity in the lateral prefrontal cortex, perhaps in an attempt to compensate for the failure of the limbic areas. The finding is consistent with other studies showing alcoholics invoking additional and sometimes higher-order brain systems to accomplish a relatively simple task at normal levels. The study compared 15 abstinent long-term alcoholics and 15 healthy, nonalcoholic controls, matched on socioeconomic backgrounds, age, education, and IQ.

[1044] Marinkovic, K., Oscar-Berman M., Urban T., O'Reilly C. E., Howard J. A., Sawyer K., et al. (2009).  Alcoholism and dampened temporal limbic activation to emotional faces. Alcoholism, Clinical and Experimental Research. 33(11), 1880 - 1892.

http://www.eurekalert.org/pub_releases/2009-08/ace-edc080509.php
http://www.eurekalert.org/pub_releases/2009-08/bumc-rfa081109.php

Binge drinking affects attention and working memory in young university students

A Spanish study of 95 first-year university students, 42 of them binge drinkers, has found that those who engaged in binge drinking required greater attentional processing during a visual working memory task in order to carry it out correctly. They also had difficulties differentiating between relevant and irrelevant stimuli. Binge drinkers are defined as males who drink five or more standard alcohol drinks, and females who drink four or more, on one occasion and within a two-hour interval. Some 40% of university students in the U.S. are considered binge drinkers.

[231] Crego, A., Holguín S R., Parada M., Mota N., Corral M., & Cadaveira F.
(2009).  Binge drinking affects attentional and visual working memory processing in young university students.
Alcoholism, Clinical and Experimental Research. 33(11), 1870 - 1879.

http://www.eurekalert.org/pub_releases/2009-08/ace-bda080509.php

HIV infection and chronic drinking together impair encoding of new experiences

A study involving 40 individuals with HIV, 38 with chronic alcoholism, 47 with both HIV and chronic alcoholism, and 39 controls, has found that although those with only one of these disorders mostly performed at levels comparable to controls on episodic and working memory tasks, those who were both positive for HIV and had a history of chronic heavy drinking were impaired on tests of immediate episodic memory (but not working memory) — meaning that they have trouble encoding new information for long-term memory. The finding is consistent with the fact that the mediotemporal lobe is affected early by both these conditions. Heavy drinking is very common among those infected with HIV.

[440] Fama, R., Rosenbloom M. J., Nichols N. B., Pfefferbaum A., & Sullivan E. V.
(2009).  Working and episodic memory in HIV infection, alcoholism, and their comorbidity: baseline and 1-year follow-up examinations.
Alcoholism, Clinical and Experimental Research. 33(10), 1815 - 1824.

http://www.eurekalert.org/pub_releases/2009-07/ace-hia072009.php

Adolescent binge drinking may compromise white matter

An imaging study of 28 teens, of whom half had a history of binge drinking (but did not meet the criteria for alcohol abuse), has found that those who had engaged in binge drinking episodes had lower coherence of white matter fibers in 18 different areas across the brain. The findings add to a growing literature indicating that adolescent alcohol involvement is associated with specific brain characteristics. White matter integrity is essential to the efficient relay of information in the brain.

[1426] McQueeny, T., Schweinsburg B. C., Schweinsburg A. D., Jacobus J., Bava S., Frank L. R., et al.
(2009).  Altered white matter integrity in adolescent binge drinkers.
Alcoholism, Clinical and Experimental Research. 33(7), 1278 - 1285.

http://www.physorg.com/news159646086.html
http://www.eurekalert.org/pub_releases/2009-04/ace-abd041509.php

Alcoholics’ brains maintain language skills at a cost

Despite the damage done by alcoholism to the frontal lobes and cerebellum, areas involved in language processing, alcoholics' language skills appear to be relatively spared from alcohol's damaging effects. A new study of 12 alcoholic males and 12 healthy controls suggests that alcoholics develop compensatory mechanisms to maintain their language skills despite alcohol's damages. The comparable performance on an auditory language task between the two groups was underlain by different neural activity (specifically, the alcoholic group showed greater activity in the left middle frontal gyrus, the right superior frontal gyrus, and the cerebellar vermis). It seems likely that this wider activity comes at the expense of other tasks, thus reducing their ability to multitask.

[926] Chanraud-Guillermo, S., Andoh J., Martelli C., Artiges E., Pallier C., Aubin H. - J., et al. (2009).  Imaging of language-related brain regions in detoxified alcoholics. Alcoholism, Clinical and Experimental Research. 33(6), 977 - 984.

http://www.eurekalert.org/pub_releases/2009-03/ace-tbm031209.php

Drinking alcohol associated with smaller brain volume

It is estimated that brain volume decreases by 1.9% per decade, accompanied by an increase in white matter lesions. Because moderate alcohol consumption has been associated with a lower risk of cardiovascular disease, it’s been thought that small amounts of alcohol might also reduce age-related declines in brain volume, although it’s known that large amounts of alcohol will reduce brain volume. However, a large, long-running study, has now found that, even at low levels of alcohol consumption, brain volume was negatively affected. Moreover, although men were more likely to be heavier drinkers, the association between drinking and brain volume was stronger in women.

[1191] Paul, C A., Au R., Fredman L., Massaro J. M., Seshadri S., DeCarli C., et al.
(2008).  Association of Alcohol Consumption With Brain Volume in the Framingham Study.
Arch Neurol. 65(10), 1363 - 1367.

http://www.eurekalert.org/pub_releases/2008-10/jaaj-daa100908.php

Heavy, chronic drinking can cause significant hippocampal tissue loss

An imaging study of 8 heavy-drinking alcoholics and 8 age and ethnicity matched non-alcoholics (all male) found that total hippocampus volume was significantly reduced among the alcoholics.

[677] Beresford, T. P., Arciniegas D. B., Alfers J., Clapp L., Martin B., Du Y., et al. (2006).  Hippocampus Volume Loss Due to Chronic Heavy Drinking. Alcoholism: Clinical and Experimental Research. 30(11), 1866 - 1870.

http://www.eurekalert.org/pub_releases/2006-10/ace-hcd101606.php

Most of the cognitive deficits associated with alcoholism recoverable

Results of a study involving middle-aged alcoholics who have been sober for six months to 13 years, suggest that long-term abstinent alcoholics can recover most of their neurocognitive deficits. However, deficits in spatial-processing abilities continued. Visuospatial processes are important for many daily activities, including driving, reading a map, assembling things, and performing tasks that require spatial orientation. The study doesn’t however know how much damage had been done when the alcoholics ceased drinking; further studies are exploring the recovery of older abstinent alcoholics who ceased drinking at different ages.

[856] Fein, G., Torres J., Price L. J., & Sclafani V. D. (2006).  Cognitive Performance in Long-Term Abstinent Alcoholic Individuals. Alcoholism: Clinical and Experimental Research. 30(9), 1538 - 1544.

http://www.eurekalert.org/pub_releases/2006-08/ace-lam082106.php

Brain atrophy occurs faster in women alcoholics

A study of 34 male and 42 female alcoholics has found that, although the women had been alcoholics for just 5.5 years on average, compared to the average 10.4 years for the men, the women had lost as much proportionate brain volume as the men. The findings are consistent with other studies suggesting that women suffer from the effects of alcohol abuse faster.

[1258] Mann, K., Ackermann K., Croissant B., Mundle G., Nakovics H., & Diehl A. (2005).  Neuroimaging of Gender Differences in Alcohol Dependence: Are Women More Vulnerable?. Alcoholism: Clinical and Experimental Research. 29(5), 896 - 901.

http://www.nature.com/news/2005/050509/full/050509-15.html

Drinking for just eight weeks impairs learning and memory in mice

It’s well established that chronic alcohol consumption can produce deficits in learning and memory. A new rodent study, however, is the first to show that continuous drinking for as little as eight weeks can produce deficits in learning and memory that last at least 12 weeks after drinking stopped — “equivalent to a human that drank six to eight beers or one bottle of wine a day every day for six years experiencing learning and memory deficits up to nine years after they stopped drinking alcohol." These deficits were global — that is, they affected long-term memory for every type of task tested. Short-term memory was not affected. Rats who drank for only four weeks did not experience the same effects.

[522] Farr, S. A., Scherrer J. F., Banks W. A., Flood J. F., & Morley J. E.
(2005).  Chronic Ethanol Consumption Impairs Learning and Memory After Cessation of Ethanol.
Alcoholism: Clinical and Experimental Research. 29(6), 971 - 982.

http://www.eurekalert.org/pub_releases/2005-06/ace-dfj060605.php

Cognitive effects of binge drinking worse for women

A new study looked at the cognitive effects of binge drinking, which apparently is on the rise in several countries, including Britain and the US. The study involved 100 healthy moderate-to-heavy social drinkers aged between 18 and 30. There were equal numbers of males and females. The study found that female binge drinkers performed worse on the working-memory and vigilance tasks than did the female non-binge drinkers.

[1311] Townshend, J. M., & Duka T.
(2005).  Binge Drinking, Cognitive Performance and Mood in a Population of Young Social Drinkers.
Alcoholism: Clinical and Experimental Research. 29(3), 317 - 325.

http://www.eurekalert.org/pub_releases/2005-03/ace-bdc030705.php

Alcohol's damaging effects on adolescent brain function

A number of speakers at Symposium speakers at the June 2004 Research Society on Alcoholism meeting in Vancouver, reported on research concerning the vulnerability of the adolescent brain to the damaging effects of alcohol. Some of the findings presented were:

  • The adolescent brain is more vulnerable than the adult brain to disruption from activities such as binge drinking. Adolescent rats that were exposed to binge drinking appear to have permanent damage in their adult brains.
  • Subtle but important brain changes occur among adolescents with Alcohol Use Disorder, resulting in a decreased ability in problem solving, verbal and non-verbal retrieval, visuospatial skills, and working memory.
  • The association between antisocial behavior during adolescence and alcoholism may be explained by abnormalities in the frontal limbic system, which appears to cause "blunted emotional reactivity".
  • Alcohol-induced memory impairments, such as "blackouts", are particularly common among young drinkers and may be at least in part due to disrupted neural plasticity in the hippocampus, which is centrally involved in the formation of autobiographical memories.

[1238] Monti, P. M., Miranda, Jr R., Nixon K., Sher K. J., Swartzwelder S. H., Tapert S. F., et al.
(2005).  Adolescence: Booze, Brains, and Behavior.
Alcoholism: Clinical and Experimental Research. 29(2), 207 - 220.

http://www.eurekalert.org/pub_releases/2005-02/ace-ade020705.php

Alcoholics can have deficits in visuoperception and frontal executive function despite sobriety

Detoxified alcoholics often have visuospatial and visuoperceptual deficits, characterized by difficulties completing tasks such as putting pieces of a puzzle together or map reading. A new study has found that, even with prolonged sobriety, alcoholics show deficits in visuoperception and frontal executive functioning of the brain. Furthermore, alcoholics utilize a more complex higher-order cognitive system (frontal executive functions) to perform the same tasks as individuals without a history of alcoholism. The potential problem with this is that if that same system is needed for a competing task, alcoholics may be at a disadvantage because that system would otherwise be engaged. The study involved 51 recently detoxified nonamnesic alcoholic men (ages 29 to 66 years) compared with 63 "normal," control men (ages 21 to 70 years).

Fama, R., Pfefferbaum, A. & Sullivan, E. V. 2004. Perceptual Learning in Detoxified Alcoholic Men: Contributions From Explicit Memory, Executive Function, and Age. Alcoholism: Clinical & Experimental Research, 28(11), 1657-1665.

http://www.eurekalert.org/pub_releases/2004-11/ace-ach110804.php

New brain cells develop during alcohol abstinence

A rat study has found that the detrimental effect of alcohol on the formation of new neurons in the adult rat hippocampus is followed by a pronounced increase in new neuron formation in the hippocampus within four-to-five weeks of abstinence. This included a twofold burst in brain cell proliferation at day seven of abstinence. The findings may have significant implications for treatment of alcoholism during recovery. The discovery of regeneration of neurons in recovery opens up new avenues of therapies aimed at regeneration of brain cells.

[393] Nixon, K., & Crews F. T. (2004).  Temporally Specific Burst in Cell Proliferation Increases Hippocampal Neurogenesis in Protracted Abstinence from Alcohol. J. Neurosci.. 24(43), 9714 - 9722.

http://www.eurekalert.org/pub_releases/2004-11/uonc-nbc110504.php

Cognitive function of alcohol abuse patients may influence treatment outcome

Years of heavy alcohol consumption are known to impair many abilities generally referred to as “executive functions.” Such functions include judgment, problem solving, decision making, planning, and social conduct. But alcohol affects executive functioning both chronically and acutely. New research has found that alcohol abuse patients show significant deficits in executive functioning (specifically, abstract reasoning, memory discrimination, and effectiveness on timed tasks) during the critical first weeks of abstinence. The finding has implications for treatment programs, as the early phases of most treatment programs for alcohol abusers commonly require working in groups, making plans for the future, inhibiting behaviors related to their addiction, and remembering specific things. It is suggested that clinicians should scale down their expectations of what patients can do until more of their executive functioning comes back. The researchers are now intending to explore how long it takes the majority of people to regain most of their executive functioning.

[194] Zinn, S., Stein R., & Swartzwelder S. H. (2004).  Executive Functioning Early in Abstinence From Alcohol. Alcoholism: Clinical and Experimental Research. 28(9), 1338 - 1346.

http://www.eurekalert.org/pub_releases/2004-09/ace-cco090504.php
http://www.eurekalert.org/pub_releases/2004-09/dumc-cfo091004.php

Brain damage found among heavy social drinkers

Almost all knowledge about brain damage due to chronic alcohol consumption has been gathered from alcoholics, generally toward the end of an institutionalized treatment program or many months into abstinence. A new study however, uses magnetic resonance technology to examine brain damage in heavy drinkers who are not in treatment and function relatively well in the community. The study found that frontal white matter NAA – generally considered to be a marker of neuronal damage – was lower in heavy drinkers than light drinkers, and was associated with lower executive and working memory functions. Some of the behaviors that could be associated with the metabolite changes include the inability to apply consequences from past actions, difficulties with abstract concepts of time and money, difficulties with storing and retrieving information, and frequently needing external motivators.

[220] Weiner, M. W., Meyerhoff D. J., Blumenfeld R., Truran D., Lindgren J., Flenniken D., et al.
(2004).  Effects of Heavy Drinking, Binge Drinking, and Family History of Alcoholism on Regional Brain Metabolites.
Alcoholism: Clinical and Experimental Research. 28(4), 650 - 661.

http://www.eurekalert.org/pub_releases/2004-04/ace-sab040704.php

Even small amounts of alcohol or anesthetics may damage the developing brain

Mouse studies suggest that even small amounts of alcohol or anesthetic drugs can trigger nerve cell death in the developing brain. The brain appears most sensitive to this effect during the development stage known as the brain growth spurt. In humans this lasts from about the sixth month of pregnancy to a child's third birthday. Nerve cells are genetically programmed to commit suicide if they fail to make synaptic connections on time. Alcohol and anesthetic drugs interfere with the brain's neurotransmitter systems and with the formation of those synaptic connections, automatically activating a signal within the neuron that directs it to commit suicide.

Olney, J.W. 2004. Perinatal Drug/Alcohol Exposure and Neuronal Suicide – Public Health Implications. Paper presented February 14 at the annual meeting of the American Association for the Advancement of Science in Seattle.

http://www.eurekalert.org/pub_releases/2004-02/wuso-sao021104.php

Hippocampal damage seen in those with alcoholic memory disorder and those with Alzheimer's

A comparison between the brains of five men with alcoholic Korsakoff's syndrome and the brains of men with Alzheimer's disease as well as the brains of healthy men, found that the brains of all Korsakoff's patients and Alzheimer's patients were comparable in significant volume loss in the hippocampus. Greater hippocampal damage (for Korsakoff's patients) and smaller hippocampal size (for Alzheimer’s) was correlated with poorer memory performance. It is suggested that, although there are of course a number of differences between these disorders, the nature of the memory impairment may be the same. Awareness of the similarities may help detection of both disorders.

[262] Sullivan, E. V., & Marsh L. (2003).  Hippocampal volume deficits in alcoholic Korsakoff's syndrome. Neurology. 61(12), 1716 - 1719.

http://www.eurekalert.org/pub_releases/2003-12/aaon-seu121503.php

Alcohol damages day-to-day memory function

A new study involving 763 participants (465 female, 298 males) used self-report questionnaires: the Prospective Memory Questionnaire (PMQ), the Everyday Memory Questionnaire (EMQ), and the UEL (University of East London) Recreational Drug Use Questionnaire, and found that heavy users of alcohol reported making consistently more errors than those who said that they consumed little or no alcohol. More specifically, those who reported higher levels of alcohol consumption were more likely to miss appointments, forget birthdays and pay bills on time (prospective memory), as well as more problems remembering whether they had done something, like locking the door or switching off the lights or oven, or where they had put items like house keys. The study also found a significant increase in reported memory problems by people who claimed to drink between 10 and 25 units each week in comparison to non-drinkers – this is within the ’safe drinking’ limits suggested by U.K. government guidelines.

[1042] Ling, J., Heffernan T. M., Buchanan T., Rodgers J., Scholey A. B., & Parrott A. C.
(2003).  Effects of Alcohol on Subjective Ratings of Prospective and Everyday Memory Deficits.
Alcoholism: Clinical and Experimental Research. 27(6), 970 - 974.

http://www.eurekalert.org/pub_releases/2003-06/ace-add060903.php

Study of alcoholics reveals connection between cerebellum and prefrontal cortex

Two functions commonly compromised by chronic alcoholism are executive functions (such as problem solving, putting things in order, working memory, doing multiple tasks at once) and balance (the ability to walk a straight line or stand on one foot, especially with eyes closed or in the dark). Executive functions are primarily processed in the prefrontal cortex, while balance and postural stability are functions of the cerebellum. Previous studies have shown that the prefrontal cortex and regions of the cerebellum are especially vulnerable to the effects of chronic alcoholism. Although these areas are spatially far apart (the former in the frontal lobes, the latter in the hindbrain), they are connected in a variety of ways, most particularly through the pons and the thalamus. An imaging study of 25 nonamnesic alcoholic men suggests that these connections may compound the damaging effects of alcohol on these brain regions, and that the cerebellum, through these connections, can exert a significant effect on functions of the prefrontal cortex.

[356] Sullivan, E. V. (2003).  Compromised Pontocerebellar and Cerebellothalamocortical Systems: Speculations on Their Contributions to Cognitive and Motor Impairment in Nonamnesic Alcoholism. Alcoholism: Clinical and Experimental Research. 27(9), 1409 - 1419.

http://www.eurekalert.org/pub_releases/2003-09/ace-amc090803.php

Alcoholics' cognitive impairment associated with impaired reaction to stress

The body secretes a hormone called cortisol in response to stress. Areas of the brain involved in memory and problem-solving are responsive to cortisol. A new study has found impaired release of cortisol in recently detoxified alcoholics when performing two tasks known to induce stress: mental arithmetic problems and a "cold pressor" task, which requires submerging one hand in ice water for 90 seconds. This was associated with lower scores on measures of problem-solving ability and memory. The study also found that, among alcoholics, the number of withdrawals from alcohol was the strongest predictor of memory impairments, but not of problem-solving ability. The greater the alcoholics' relative cortisol levels were during alcohol withdrawal, the more likely they were to have low scores on one of the problem-solving tests. Nonalcoholic participants showed a connection between higher post-stress cortisol levels and impaired memory, a finding supported by earlier research.

[340] Errico, A. L., King A. C., Lovallo W. R., & Parsons O. A. (2002).  Cortisol Dysregulation and Cognitive Impairment in Abstinent Male Alcoholics. Alcoholism: Clinical and Experimental Research. 26(8), 1198 - 1204.

http://www.eurekalert.org/pub_releases/2002-08/cfta-air080902.php

tags lifestyle: 

tags problems: 

Post-surgery cognitive decline

Older news items (pre-2010) brought over from the old website

Cognitive decline after noncardiac surgery

Older surgical patients at greater risk for developing cognitive problems

There’s been quite a lot of research on the effects of cardiac surgery on cognitive function, but less is known about the effects of any surgery. Now a study of more than 1000 adult patients of different ages has tested memory and cognitive function before undergoing elective non-cardiac surgery, at the time of hospital discharge, and three months after surgery. It was found that many patients, regardless of age, experienced postoperative cognitive dysfunction (POCD) at the time they left the hospital (36.6% of young adults, 30.4% of the middle-aged, 41.4% of elderly). But three months later, those aged 60 and older were more than twice as likely to exhibit POCD (12.7% compared to less than 6% for both young and middle-aged). POCD was more common among those patients with lower educational level and a history of a stroke that had left no noticeable neurologic impairment. Those with POCD at both the time of hospital discharge and three months after surgery also were more likely to die within the first year after surgery. The reason for this is unclear, but it’s speculated that patients with prolonged cognitive dysfunction might be less able to take medicines correctly or may not recognize the need to seek medical care for symptoms of complications. [1]

Cognitive decline after heart bypass

More evidence bypass surgery not responsible for cognitive impairment

A 6-year study of 326 heart patients has found no differences in brain impairment between those who had on-pump coronary artery bypass surgery (152 patients), off-pump bypass surgery patients (75 patients), and those who had drugs and arterial stents to keep their blood vessels open instead of bypass surgery (99 patients). However, all of them were found to have experienced significant cognitive decline over the six-year study period on tests of verbal memory, visual memory, visuoconstruction, language, motor speed, psychomotor speed, attention, and executive function, when compared to 69 heart-healthy people who had no known risk factors for coronary artery disease. The findings provide more evidence that it is the disease and not the surgery that causes long-term cognitive problems. [2]

Long-term cognitive decline in bypass patients not due to surgery

Another study has come out supporting the view that coronary bypass patients have no greater risk of long-term cognitive decline than patients not undergoing surgery. The study involved 152 patients who had bypass surgery and 92 patients with coronary artery disease who did not have surgical intervention. Patients had memory and other cognitive tests at the beginning of the study period, and after 3, 12, 36 and 72 months. The results showed that there were no significant differences in cognitive scores between the two groups at the beginning of the study. Both groups showed modest decline in cognitive performance during the study period, but there were no significant differences in the degree of decline between the groups after six years. It was suggested that the decline in both groups was related to the presence of risk factors for vascular disease. [3]

Inflammatory system genes linked to cognitive decline after heart surgery

The finding that people with variants of two genes involved in the inflammatory system appear to be protected from suffering a decline in mental function following heart surgery raises the possibility that therapy involving drugs known to dampen the inflammatory response may be effective in preventing cognitive decline after heart surgery. The specific genes involved were those for C-reactive protein (which plays an important role in the body’s initial response to injury) and P-selectin (which helps recruit circulating white blood cells to the site of an injury). Patients with the variation of the C-reactive protein gene were 20.6% less likely to suffer mental decline, and patients with the P-selectin variant had a 15.2% risk reduction. The risk of cognitive decline for those with both gene variants was only 17% compared to 43% for patients who had neither variant. [4]

'Off-pump' CABG surgery appears to have no benefit on cognitive or cardiac outcomes at 5 years

A five-year study of 281 cardiac patients, half of whom received off-pump coronary artery bypass surgery and half on-pump surgery, has found that there was no difference in cognitive performance five years after surgery. The findings suggest that factors other than cardiopulmonary bypass may be responsible for cognitive decline, such as anesthesia and the generalized inflammatory response that is associated with major surgical procedures. [5]

Cognitive loss following coronary artery bypass surgery due to surgical technique?

A surgical strategy designed to minimize trauma to the body's largest artery – the aorta – during heart bypass surgery can significantly reduce cognitive loss that often follows the operation. The study found that at least 60% of patients showed neurological deficits following bypass surgery, but that at 6 months, 57% of patients who had traditional surgery still had deficits while only 32% of those who didn’t use the heart-lung machine during surgery, and 30% of those who had the new surgical technique still had deficits. Researchers conclude that surgical technique is the primary cause of cognitive decline following bypass surgery. [6]

Use of heart pump during bypass surgery not implicated in cognitive decline

A study involving 380 individuals has found that those patients undergoing coronary artery bypass grafting (CABG) surgery that used a cardiopulmonary heart pump had no significant differences in their mental functions compared to CABG patients whose surgery did not involve a heart pump. Patients with coronary heart disease all performed lower on cognitive tests than healthy controls, prior to surgery. By three months, both cardiac patients who had undergone surgery (with or without use of a heart pump) and those who had not, had improved cognitive function. [7]

Review finds bypass surgery free of long-term brain effects for most

A broad retrospective review of the effects of coronary artery bypass surgery on cognitive functions concludes that, although the research confirms the existence of mild deficits in the period up to three months after surgery, the procedure itself probably does not cause late or permanent neurological effects. Rather, they argue, the late cognitive declines seen in some long-term studies are for most people likely associated with progression of underlying conditions such as cerebrovascular disease. However, this is not true for all. The exceptions might include older patients and those with risk factors for cerebrovascular disease or a history of stroke. [8]

Elderly experience long-term cognitive decline after surgery

Researchers have found that two years after major non-cardiac surgery, 42% of elderly patients will have experienced a measurable cognitive decline. 59% of patients experienced cognitive decline immediately after surgery — these are the ones at greatest risk of long-term decline. Three months after surgery, 34% of patients had cognitive declines. The study involved 354 patients, with an average age of 69.5 years. [9]

Lower temperatures improve outcomes after bypass surgery

One of the possible adverse effects of cardiac bypass surgery is cognitive decline. Researchers have found that patients who were allowed an additional 10 to 12 minutes to return to normal body temperature after surgery scored almost one-third better on standard tests of cognition six weeks after surgery. (In order to protect the brain and other organs from damage while the heart is stopped during surgery, physicians cool a patient's blood as it passes through a heart-lung machine. However, toward the end of the operation, this blood needs to be rewarmed.) [10]

Cognitive decline after bypass surgery appears more transient than feared

Recent studies have found a high occurrence of cognitive problems in patients who undergo coronary artery bypass surgery, with such problems still found six weeks after surgery. In a new study comparing 140 patients who underwent bypass surgery and a second group of 92 coronary artery disease patients who did not have surgery, no differences in cognitive abilities were found when patients were re-tested at three and 12 months. This supports recent research suggesting that it is the disease itself that is the major problem, rather than the surgery. [11]

Lowered immunity puts older coronary bypass patients at higher risk for cognitive decline

Older patients with lowered immunity to certain common bacteria found in the gastrointestinal tract are more likely than younger patients to suffer cognitive decline after coronary artery bypass surgery. [12]

Cognitive impairment following bypass surgery may last longer than thought

More support for a link between cardiopulmonary bypass surgery and cognitive impairment comes from a new study. In particular, it seems, that attention may be most affected. The study also found evidence of longer-lasting cognitive decline than previously thought. Bypass patients also demonstrated poorer cognitive performance before the surgery, and it is now being suggested that it may be the disease itself that is the major problem, rather than the surgery itself. This is consistent with recent research connecting cardiovascular risk factors with risk factors for cognitive decline. [13]

Fever immediately after heart bypass surgery associated with cognitive decline

Elevated temperatures within 8-10 hours after surgery are often seen in patients who have undergone coronary bypass surgery. This has not however been regarded as anything other than a nuisance. Many bypass patients also suffer measurable cognitive decline. A new study reports on a relationship between these fevers and cognitive decline six weeks following surgery. Patients who suffered the highest post-operative temperatures also suffered the highest amount of cognitive decline. [14]

More on implications of having the Alzheimer's gene

Researchers have found an association between nerve cell changes associated with aging and the presence of a variation of the apolipoprotein gene known as apolipoprotein E4 (APOE4). This form is carried by approximately 25% of the population and has been linked to increased risk of Alzheimer's disease, cardiovascular disease and memory loss after head injury or bypass surgery. [15]

Frequency of cognitive decline after bypass surgery>

Heart bypasses are becoming increasingly common - in the U.S., more than half a million people undergo coronary-artery bypass grafting (CABG) each year. A common side-effect of the procedure is postoperative cognitive decline (frequency of occurrence estimates range from 33% to 82%, depending on the method of evaluation used). A recent study looked at the longer-term picture: in this study, cognitive decline was found in 53% of the patients at time of discharge; at 6 weeks, the rate was assessed at 36%; at 6 months, 24%. However, five years after the surgery the rate of cognitive decline was 42%. Older age, a lower level of education, a higher preoperative score for cognitive function, and the presence of cognitive decline at discharge were all predictors of cognitive decline at 5 years after CABG. Of these, the most significant predictor was a decline in cognition seen at discharge.
Note that there was no control group, so these results must be treated with caution. Note also that short-term declines in cognitive function are also reported in elderly subjects after non-cardiac surgery, and this can persist in a proportion of these patients - in fact, in 10% after 2 years. [16]

1.Monk, T.G. et al. 2008. Predictors of Cognitive Dysfunction after Major Noncardiac Surgery. Anesthesiology, 108(1), 18-30.
Price, C.C.; Garvan, C.W. & Monk, T.G. 2008. Type and Severity of Cognitive Decline in Older Adults after Noncardiac Surgery. Anesthesiology, 108(1), 8-17. Press release

2.Selnes, O.A. et al. 2009. Do Management Strategies for Coronary Artery Disease Influence 6-Year Cognitive Outcomes? Annals of Thoracic Surgery, 88, 445-454. Press release

3.Selnes, O.A. et al. 2008. Cognition 6 Years After Surgical or Medical Therapy for Coronary Artery Disease. Annals of Neurology, 63, 581-590. Press release Press release

4.Mathew, J.P. et al. 2007. Genetic Variants in P-Selectin and C-Reactive Protein Influence Susceptibility to Cognitive Decline After Cardiac Surgery. Journal of the American College of Cardiology, 49, 1934 - 1942. Press release

5.van Dijk, D. et al. 2007. Cognitive and Cardiac Outcomes 5 Years After Off-Pump vs On-Pump Coronary Artery Bypass Graft Surgery. JAMA, 297, 701-708. Press release

6.Hammon, J.W., Stump, D.A., Butterworth, J.F., Moody, D.M., Rorie, K., Deal, D.D., Kincaid, E.H., Oaks, T.E. & Kon, N.D. 2006. Single crossclamp improves 6-month cognitive outcome in high-risk coronary bypass patients: The effect of reduced aortic manipulation.The Journal of Thoracic and Cardiovascular Surgery, 131 (1), 114-121. Press release

7.McKhann, G.M., Grega, M.A., Borowicz, L.M.Jr, Bailey, M.M., Barry, S.J.E., Zeger, S.L., Baumgartner, W.A. & Selnes, O.A. 2005. Is there cognitive decline 1 year after CABG?: Comparison with surgical and nonsurgical controls. Neurology, 65, 991-999. Press release

8.Selnes, O.A. & McKhann, G.M. 2005. Neurocognitive Complications after Coronary Artery Bypass Surgery. Annals of Neurology, Published Online: April 25, 2005 (DOI: 10.1002/ana.20481) Press release

9.Monk, T. et al. 2004. Paper presented October 26 at the annual scientific sessions of the American Society of Anesthesiologists in Las Vegas. Press release

10.Grocott, H. et al. 2004. Paper presented April 26 at the annual scientific sessions of the Society of Cardiovascular Anesthesiologists. Press release

11.Selnes, O.A., Grega, M.A., Borowicz, L.M. Jr , Royall, R.M., McKhann, G.M. & Baumgartner, W.A. 2003. Cognitive changes with coronary artery disease: a prospective study of coronary artery bypass graft patients and nonsurgical controls. The Annals of Thoracic Surgery, 75 (5), 1377-1386. Press release

12.Mathew, J.P., Grocott, H.P., Phillips-Bute, B., Stafford-Smith, M., Laskowitz, D.T., Rossignol, D., Blumenthal, J.A. & Newman, M.F. 2003. Lower Endotoxin Immunity Predicts Increased Cognitive Dysfunction in Elderly Patients After Cardiac Surgery. Stroke, 34, 508. Press release

13.Keith, J.R., Puente, A.E., Malcolmson, K.L., Tartt, S., Coleman, A.E. & Marks, H.F. Jr. 2002. Assessing Postoperative Cognitive Change After Cardiopulmonary Bypass Surgery. Neuropsychology, 16(3), 411-21. Press release

14.Grocott, H.P., Mackensen, G.B., Grogore, A.M., Mathew, J., Reves, J.G., Phillips-Bute, B., Smith, P.K. & Newman, M.F. 2002. Postoperative Hyperthermia Is Associated With Cognitive Dysfunction After Coronary Artery Bypass Graft Surgery. Stroke, 33, 537-541. Press release

15.Doraiswamy, P.M. et al. 2002. Paper presented February 25 at the 15th annual meeting of the American Association for Geriatric Psychiatry in Orlando, Fla. Press release

16.Newman, M. F., Kirchner, J. L., Phillips-Bute, B., Gaver, V., Grocott, H., Jones, R. H., Mark, D. B., et al. (2001). Longitudinal Assessment of Neurocognitive Function after Coronary-Artery Bypass Surgery. N Engl J Med, 344(6), 395-402. Press release

tags development: 

tags problems: 

Dietary supplements

Older news items (pre-2010) brought over from the old website

Evidence mounts against DHEA use in treating cognitive decline

DHEA is a naturally-occurring hormone in the human body that declines with age. Previous research looking at the effect of DHEA supplementation on cognitive function and quality-of-life has produced inconsistent results. In the first long-term study (12 months) of healthy older adults, 110 men and 115 women aged 55-85 received either daily 50 mg doses of DHEA or a similar looking placebo pill for 1 year. It was found that, although youthful levels of DHEA were restored in the treatment group, the supplements had no benefits for cognitive function or quality-of-life in this representative sample.

[1222] Kritz-Silverstein, D., von Mühlen D., Laughlin G. A., & Bettencourt R.
(2008).  Effects of Dehydroepiandrosterone Supplementation on Cognitive Function and Quality of Life: The DHEA and Well-Ness (DAWN) Trial.
Journal of the American Geriatrics Society. 56(7), 1292 - 1298.

http://www.eurekalert.org/pub_releases/2008-05/w-ema052108.php

French maritime pine bark improves memory in elderly

A double-blind, placebo controlled, matched pairs study examined the effects of Pycnogenol (an antioxidant plant extract from the bark of the French maritime pine tree) on a range of cognitive and biochemical measures in 101 senior individuals aged 60-85 years old. Participants had a daily dose of 150mg for three months. Pycnogenol improved both numerical working memory as well as spatial working memory. Blood samples revealed that F2-isoprostanes significantly decreased with Pycnogenol, a sign of reduced oxidation of nerve membranes, suggesting that the antioxidant activity of Pycnogenol plays a major role for the clinical effects. Several recent research studies have found Pycnogenol reduced ADHD symptoms such as hyperactivity and improved attention, concentration and motor-visual coordination in children with ADHD. Pycnogenol extract has been studied for 35 years and is available in more than 600 dietary supplements.

[2425] Ryan, J., Croft K., Mori T., Wesnes K., Spong J., Downey L., et al.
(2008).  An examination of the effects of the antioxidant Pycnogenol(R) on cognitive performance, serum lipid profile, endocrinological and oxidative stress biomarkers in an elderly population.
J Psychopharmacol. 22(5), 553 - 562.

http://www.eurekalert.org/pub_releases/2008-03/mg-nsp031708.php

Long-term beta carotene supplementation may help prevent cognitive decline

A large, long-running study has found that men who took beta carotene supplements for 15 years or longer had significantly higher scores on several cognitive tests compared with men who took placebo. There was no such effect in those men who took the supplements for a year. The researchers suggest that although the benefits were modest in themselves, they may predict substantial differences in eventual risk of dementia. However, it should be noted that beta carotene is not without risks—for example, it may increase the risk of lung cancer in smokers — and that it would be premature to advise use of such supplements.

[710] Grodstein, F., Kang J H., Glynn R. J., Cook N. R., & Gaziano M. J.
(2007).  A Randomized Trial of Beta Carotene Supplementation and Cognitive Function in Men: The Physicians' Health Study II.
Arch Intern Med. 167(20), 2184 - 2190.

http://www.eurekalert.org/pub_releases/2007-11/jaaj-lbc110807.php

Dietary supplements improve old rats' memory and energy levels

After only a month, older rats fed two chemicals normally found in the body's cells and available as dietary supplements — acetyl-L-carnitine and an antioxidant, alpha-lipoic acid — performed better on memory tests, and had noticeably more energy (on a par with a “middle-aged” rat). It is thought that these chemicals act on the mitochondria, the “power-houses” of the cells. Mitochondria are increasingly being implicated as especially vulnerable to the aging process. Carnitine is a natural compound produced in the cell and obtained in the diet through meats and vegetables. It has been shown to improve balance and short-term memory in human. Lipoic acid is found in green, leafy vegetables.
The University of California has patented use of the combination of the two supplements to rejuvenate cells. Human clinical trials are currently underway.

[1215] Hagen, T. M., Liu J., Lykkesfeldt J., Wehr C. M., Ingersoll R. T., Vinarsky V., et al.
(2002).  Feeding acetyl-l-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress.
Proceedings of the National Academy of Sciences of the United States of America. 99(4), 1870 - 1875.

[618] Liu, J., Head E., Gharib A. M., Yuan W., Ingersoll R. T., Hagen T. M., et al.
(2002).  Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: Partial reversal by feeding acetyl-l-carnitine and/or R-α-lipoic acid.
Proceedings of the National Academy of Sciences of the United States of America. 99(4), 2356 - 2361.

[1232] Liu, J., Killilea D. W., & Ames B. N.
(2002).  Age-associated mitochondrial oxidative decay: Improvement of carnitine acetyltransferase substrate-binding affinity and activity in brain by feeding old rats acetyl-l- carnitine and/or R-α-lipoic acid.
Proceedings of the National Academy of Sciences of the United States of America. 99(4), 1876 - 1881.

http://www.eurekalert.org/pub_releases/2002-02/uoc--dsm021502.php
http://www.eurekalert.org/pub_releases/2002-02/osu-crr021902.htm

tags lifestyle: 

tags problems: 

Pages

Subscribe to RSS - aging