A study involving 382 older adults (average age 75) followed for around five years, has found that those who don’t get enough vitamin D may experience cognitive decline at a much faster rate than people who have adequate vitamin D.
Participants included 17.5% with dementia at the beginning of the study, 32.7% with MCI, and 49.5% cognitively healthy.
Those with dementia had lower levels of vitamin D than the other two groups.
A study involving 218 participants aged 18-88 has looked at the effects of age on the brain activity of participants viewing an edited version of a 1961 Hitchcock TV episode (given that participants viewed the movie while in a MRI machine, the 25 minute episode was condensed to 8 minutes).
While many studies have looked at how age changes brain function, the stimuli used have typically been quite simple. This thriller-type story provides more complex and naturalistic stimuli.
A study involving 100 healthy older adults (aged 60-80) has found that those with higher levels of physical activity showed more variable spontaneous brain activity in certain brain regions (including the precuneus, hippocampus, medial and lateral prefrontal, and temporal cortices). Moreover, this relationship was positively associated with better white-matter structure.
Higher rates of activity when the brain is “at rest” have previously been shown to be associated with better cognitive performance in older adults, especially in IQ and memory.
A large, five-year study challenges the idea that omega-3 fatty acids can slow age-related cognitive decline. The study, involving 4,000 older adults, was part of the Age-Related Eye Disease Study (AREDS), which established that daily high doses of certain antioxidants and minerals can help slow the progression of age-related macular degeneration. However, a follow-up study found the addition of omega-3 fatty acids to the AREDS formula made no difference.
A large, two-year study challenges the evidence that regular exercise helps prevent age-related cognitive decline.
The study involved 1,635 older adults (70-89) who were enrolled in the Lifestyle Interventions and Independence for Elders (LIFE) study. They were sedentary adults who were at risk for mobility disability but able to walk about a quarter mile. Participants had no significant cognitive impairment (as measured by the MMSE) at the beginning of the study. Around 90% (1476) made it to the end of the study, and were included in the analysis.
More evidence for the benefits of the Mediterranean diet for fighting age-related cognitive decline comes from a large 5-year study. The study involved 960 older adults, whose cognitive change was assessed over 4.7 years. Those who followed the MIND diet more rigorously showed an equivalent of being 7.5 years younger cognitively than those who followed the diet least.
The Mediterranean-DASH Diet Intervention for Neurodegenerative Delay is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. It requires at least:
A six-month pilot study involving 101 healthy older adults (65+), who were randomly put into one of three exercise interventions or a no-change control, has found that the exercise groups all showed significant improvement in visual-spatial processing and attention, with more improvement in visual-spatial processing occurring in those with higher levels of exercise.
I've reported before on the idea that the drop in working memory capacity commonly seen in old age is related to the equally typical increase in distractability. Studies of brain activity have also indicated that lower WMC is correlated with greater storage of distractor information. So those with higher WMC, it's thought, are better at filtering out distraction and focusing only on the pertinent information. Older adults may show a reduced WMC, therefore, because their ability to ignore distraction and irrelevancies has declined.
Why does that happen?
A review of meditation research reported in January last year concluded that there were insufficient good studies to allow us to say that meditation clearly improves attention and cognition. Studies from 2014 suggest three factors that might be part of the reason for inconsistent research findings:
In 2013 I reported briefly on a pilot study showing that “super-agers” — those over 80 years old who have the brains and cognitive powers more typical of people decades younger — had an unusually large anterior cingulate cortex, with four times as many von Economo neurons.