seniors

Previous research has indicated that obesity in middle-age is linked to higher risk of cognitive decline and dementia in old age. Now a study of 32 middle-aged adults (40-60) has revealed that although obese, overweight and normal-weight participants all performed equally well on a difficult cognitive task (a working memory task called the 2-Back task), obese individuals displayed significantly lower activation in the right inferior parietal cortex.

Inflammation in the brain appears to be a key contributor to age-related memory problems, and it may be that this has to do with the dysregulation of microglia that, previous research has shown, occurs with age. As these specialized support cells in the brain do normally when there’s an infection, with age microglia start to produce excessive cytokines, some of which result in the typical behaviors that accompany illness (sleepiness, appetite loss, cognitive deficits and depression).

A long-running study involving 1,157 healthy older adults (65+) who were scored on a 5-point scale according to how often they participated in mental activities such as listening to the radio, watching television, reading, playing games and going to a museum, has found that this score is correlated to the rate of cognitive decline in later years.

Confirming earlier research, a study involving 257 older adults (average age 75) has found that a two-minute questionnaire filled out by a close friend or family member is more accurate that standard cognitive tests in detecting early signs of Alzheimer’s.

The AD8 asks questions about changes in everyday activities:

Low levels of DHA, an omega-3 fatty acid, have been found in the brains of those with Alzheimer's disease, but the reason has not been known. A new study has found that lower levels of DHA in the liver (where most brain DHA is manufactured) were correlated with greater cognitive problems in the Alzheimer’s patients. Moreover, comparison of postmortem livers from Alzheimer’s patients and controls found reduced expression of a protein that converts a precursor acid into DHA, meaning the liver was less able to make DHA from food.

A review of brain imaging and occupation data from 588 patients diagnosed with frontotemporal dementia has found that among the dementias affecting those 65 years and younger, FTD is as common as Alzheimer's disease. The study also found that the side of the brain first attacked (unlike Alzheimer’s, FTD typically begins with tissue loss in one hemisphere) is influenced by the person’s occupation.

Findings from the long-running Religious Orders Study, from 354 Catholic nuns and priests who were given annual cognitive tests for up to 13 years before having their brains examined post-mortem, has revealed that even the very early cognitive impairments we regard as normal in aging are associated with dementia pathology. Although pathology in the form of neurofibrillary tangles, Lewy bodies, and cerebral infarctions were all associated with rapid decline, they were also associated with “normal” mild impairment.

Type 2 diabetes is known to increase the risk of cognitive impairment in old age. Now analysis of data from 41 older diabetics (aged 55-81) and 458 matched controls in the Victoria Longitudinal Study has revealed that several other factors make it more likely that an older diabetic will develop cognitive impairment. These factors are: having higher (though still normal) blood pressure, having gait and balance problems, and/or reporting yourself to be in bad health regardless of actual problems.

A study involving 2,050 people aged 70 to 89 has found that mild cognitive impairment was 1.5 times more common in men than women. Among the 1,969 who did not have dementia, over 16% (329) had MCI — around 11% amnestic MCI (MCI-A) and 5% non-amnestic (MCI-MCD). A total of 19% of men had MCI, compared to 14% of women. MCI was also more common among the never-married, those with the APOEe4 (Alzheimer’s risk) gene, and those with less education.

Reports on cognitive decline with age have, over the years, come out with two general findings: older adults do significantly worse than younger adults; older adults are just as good as younger adults. Part of the problem is that there are two different approaches to studying this, each with their own specific bias. You can keep testing the same group of people as they get older — the problem with this is that they get more and more practiced, which mitigates the effects of age.