It is common for people to feel as they get older that they more frequently experience occasions when they cannot immediately retrieve a word they know perfectly well ("it's on the tip of my tongue").
Latest Research News
A mouse study has found that obese mice had high levels of interleukin 1 in both their blood and their brains, and this was associated with:
- high levels of inflammation,
- low levels of a biochemical important to synapse function, and
- impaired cognitive function.
Moreover, when fat was removed from the obese mice, interleukin levels dropped dramatically, and cognitive performance improved.
Putting obese mice on an exercise program had a similar effect, even though they didn’t lose weight — but they gained muscle and lost fat.
Data from 133,479 women in the California Teachers Study has found that those who reported doing moderate physical activity (such as brisk walking) in the three years before enrolling in the study were 20% less likely to suffer a stroke than women who reported no activity. More strenuous activity didn’t further reduce risk.
A large Danish study comparing two groups of nonagenarians born 10 years apart has found that not only were people born in 1915 nearly a third (32%) more likely to reach the age of 95 than those in the 1905 cohort, but members of the group born in 1915 performed significantly better on tests of cognitive ability and activities of daily living. Additionally, significantly more members of the later cohort scored maximally on the MMSE (23% vs 13% of the earlier cohort).
Following a previous study linking higher maternal levels of two common chemicals with slower mental and motor development in preschoolers, a new study has found that this effect continues into school age.
The study involved 328 inner-city mothers and their children. The mothers' levels of prenatal urinary metabolites of di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBzP), di-isobutyl phthalate (DiBP), di-2-ethylhexyl phthalate and diethyl phthalate were measured in late pregnancy. IQ tests were given to the children at age 7.
An examination of the brains of three groups of deceased individuals (13 cognitively normal, aged 20-66; 16 non-demented older adults, aged 70-99; 21 individuals with Alzheimer's, aged 60-95) has found that amyloid starts to accumulate and clump inside basal forebrain cholinergic neurons in young adulthood. Other neurons didn't show the same extent of amyloid accumulation. Basal forebrain cholinergic neurons are the first to be affected, and to die, in aging and Alzheimer's.
A study involving both mice and human cells adds to evidence that stress is a risk factor for Alzheimer's.
The study found that mice who were subjected to acute stress had more amyloid-beta protein in their brains than a control group. Moreover, they had more of a specific form of the protein, one that has a particularly pernicious role in the development of Alzheimer's disease.
When human neurons were treated with the stress hormone corticotrophin releasing factor (CRF), there was also a significant increase in the amyloid proteins.
Data from 876 patients (average age 78) in the 30-year Cardiovascular Health Study show that virtually any type of aerobic physical activity can improve brain volume and reduce Alzheimer's risk.
An interesting new theory for PTSD suggests that the root of the problem lies in context processing problems.
Context processing allows people and animals to recognize that a particular stimulus may require different responses depending on the context in which it is encountered. So, for example, a lion in the zoo evokes a different response than one encountered in your backyard.
Context processing involves the hippocampus, and its connections to the prefrontal cortex and the amygdala. Research has shown that activity in these brain areas is disrupted in those with PTSD.
Poor sleep has been associated with Alzheimer's disease risk, but a new study suggests a specific aspect of sleep is important.
The study, involving 119 older adults (60+), of whom 80% were cognitively normal and the remainder very mildly impaired, found that decreased slow-wave sleep coincided with higher levels of tau in the brain and a higher tau-to-amyloid ratio in the cerebrospinal fluid.