A new American analysis has found that following the well-known Mediterranean diet appears to be linked with higher cognitive, or brain, function.
Led by researchers at the US National Eye Institute, part of the US National Institutes of Health, the analysis looked at data on 7,756 participants taking part in two major studies investigating eye disease: the Age-Related Eye Disease Study (Areds) and Areds2.
Both of these studies have assessed the effect of vitamins on age-related macular degeneration (AMD).
AMD is a neurodegenerative condition that affects the retina, causing loss of central vision and affecting everyday abilities such as seeing faces, driving, reading and writing.
To assess how diet could also affect cognition, the researchers asked the participants to complete questionnaires at the start of the study about their average consumption of nine components of the Mediterranean diet.
This is a diet high in whole fruits, vegetables, whole grains, nuts, legumes, fish and olive oil, and low in red meat and alcohol.
To look at participants’ cognition, Areds tested the subjects’ cognitive function after five years, while Areds2 tested cognitive function at the start of the study and again two, four and 10 years later.
The findings, published in the journal Alzheimer’s and Dementia, showed that those who followed the Mediterranean diet more closely had the lowest risk of cognitive impairment.
In particular, eating plenty of fish and vegetables appeared to have the greatest protective effect, with Areds2 finding that after ten years of following the participants, those with the highest fish consumption had the slowest rate of cognitive decline.
In addition, the team found that participants with the ApoE gene, which increases the risk of Alzheimer’s disease, had lower cognitive function scores and greater cognitive decline, on average, than those without the gene.
However, following the Mediterranean diet brought similar benefits to those with and without the ApoE gene, suggesting that the cognitive benefits of diet are independent of genetic risk for Alzheimer’s disease.
“We do not always pay attention to our diets. We need to explore how nutrition affects the brain and the eye,” said lead author of both studies Dr Emily Chew. – AFP Relaxnews