seniors

It’s now well established that older brains tend to find it harder to filter out irrelevant information. But now a new study suggests that that isn’t all bad. The study compared the performance of 24 younger adults (17-29) and 24 older adults (60-73) on two memory tasks separated by a 10-minute break. In the first task, they were shown pictures overlapped by irrelevant words, told to ignore the words and concentrate on the pictures only, and to respond every time the same picture appeared twice in a row.

A study involving 155 women aged 65-75 has found that those who participated in resistance training once or twice weekly for a year significantly improved their selective attention (maintaining mental focus) and conflict resolution (as well as muscular function of course!), compared to those who participated in twice-weekly balance and tone training. Performance on the Stroop test improved by 12.6% and 10.9% in the once-weekly and twice-weekly resistance training groups respectively, while it deteriorated by 0.5% in the balance and tone group.

A number of rodent studies have shown that blueberries can improve aging memory; now for the first time, a human study provides evidence. In the small study, nine older adults (mean age 76) with mild cognitive impairment (MCI) drank the equivalent of 2-2 l/2 cups of a commercially available blueberry juice every day. After three months they showed significantly improved paired associate learning and word list recall. The findings will of course have to be confirmed by larger trials, but they are consistent with other research.

Rapamycin, a drug that keeps the immune system from attacking transplanted organs, was recently found to extend the life span of aged research mice. Now a study involving genetically engineered mice has found that 10 weeks of taking the drug improved learning and memory and reduced Alzheimer's-like damage in the brain.

A study involving 57 cognitively healthy older adults has found that those who showed decreased memory performance two years later (20 of the 57) had higher baseline levels of phosphorylated tau231 in the cerebrospinal fluid, and more atrophy in the medial temporal lobe. Higher levels of damaged tau protein were associated with reductions in medial temporal lobe gray matter. The finding may be useful in early diagnosis of Alzheimer’s disease.

Midlife hypertension has been confirmed as a risk factor for the development of dementia in late life, but there have been conflicting findings about the role of late-life hypertension. Now a five-year study involving 990 older adults (average age 83) with cognitive impairment but no dementia, has found that dementia developed at around the same rate among participants with and without hypertension, among those with memory dysfunction alone and those with both memory and executive dysfunction.

By following 597 Alzheimer’s patients over 15 years, researchers have determined that a simple progression rate can be calculated at the initial visit, using symptom onset and present performance, and that this can reliably identify slow, intermediate and rapid progression.

A survey of more than 100 studies involving PIB-PET, a diagnostic tool that involves injecting a radiotracer called Pittsburgh compound B into the brain via the bloodstream, and imaging the brain with positron emission tomography (PET), has confirmed its sensitivity in detecting amyloid-beta protein plaques. The tool is not yet commercially available. The study also provides strong evidence supporting the theory that accumulation of amyloid-beta protein plaques in the brain is central to the development of Alzheimer’s.

Data from 330 participants in The 90+ Study, of whom 70% were women, has revealed an overall annual incidence rate of 18.2% for dementia, rising from 12.7% per year in the 90-94 age group, to 21.2% in the 95-99 age group and 40.7% per year in the 100+ age group. 60% of the cases were attributed to Alzheimer's disease, 22% vascular dementia, 9% mixed Alzheimer’s and vascular dementia and 9% other/unknown. Unlike previous findings, rates were very similar for men and women.

A study involving over 1000 older men and women (60-75) with type-2 diabetes has found that those with higher levels of the stress hormone cortisol in their blood are more likely to have experienced cognitive decline. Higher fasting cortisol levels were associated with greater estimated cognitive decline in general intelligence, working memory and processing speed. This was independent of mood, education, metabolic variables and cardiovascular disease. Strategies aimed at lowering stress levels may be helpful for older diabetics.