seniors

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.

A study involving 105 people with Alzheimer's disease and 125 healthy older adults has compared cognitive function and brain shrinkage in those aged 60-75 and those aged 80+.

A three-year study following 1,262 healthy older Canadians (aged 67-84) has found that, among those who exercised little, those who had high-salt diets showed significantly greater cognitive decline. On the bright side, sedentary older adults who had low-salt consumption did not show cognitive decline over the three years. And those who had higher levels of physical activity did not show any association between salt and cognition.

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.

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.

Dietary changes affect levels of biomarkers associated with Alzheimer's

In a study involving 20 healthy older adults (mean age 69.3) and 29 older adults who had amnestic mild cognitive impairment (mean age 67.6), half the participants were randomly assigned to a high–saturated fat/high–simple carbohydrate diet (HIGH) and half to a low–saturated fat/low–simple carbohydrate diet (LOW) for four weeks, in order to investigate the effects on biomarkers associated with Alzheimer’s.

Sleep apnea linked to later dementia

A study involving 298 older women with sleep problems found that those who had disordered breathing (such as sleep apnea) were significantly more likely to develop dementia or mild cognitive impairment.

Functional impairment good indicator of mild cognitive impairment

Following on from research showing that long-term meditation is associated with gray matter increases across the brain, an imaging study involving 27 long-term meditators (average age 52) and 27 controls (matched by age and sex) has revealed pronounced differences in white-matter connectivity between their brains.

Another study showing the value of exercise for preserving your mental faculties in old age. This time it has to do with the development of small brain lesions or infarcts called "silent strokes." Don’t let the words “small” and “silent” fool you — these lesions have been linked to memory problems and even dementia, as well as stroke, an increased risk of falls and impaired mobility.