Flavanol-rich foods may protect against age-related memory loss

NEW YORK – Sticking to a Western-style diet may exacerbate memory loss in old age, suggests a new study. However, a team from Columbia University in New York says that people who fill up on flavanols — nutrients that are abundant in some fruits, vegetables and other foods — face a lower likelihood of developing age-related cognitive decline.

The study found that replenishing flavanols in mildly deficient individuals over the age of 60 significantly improved their performance on mental tests. This groundbreaking study is the first to make such a link, potentially paving the way for a new brain health screening program. It suggests that flavanol supplements could be prescribed to individuals in their 40s and 50s to mitigate the risk of Alzheimer’s disease in later life.

The improvement among study participants on low-flavanol diets was substantial and raises the possibility of using flavanol-rich diets or supplements to improve cognitive function in older adults, says Adam Brickman, PhD, professor of neuropsychology at Vagelos College. of Physicians and Surgeons of Columbia University. and co-lead of the study.

The number of dementia cases worldwide is projected to triple to more than 150 million by 2050. This finding also adds to evidence suggesting that the aging brain, just like the developing brain in children, requires specific nutrients for optimal health.

The identification of nutrients critical to the proper development of a newborn’s nervous system was the crowning achievement of 20^th nutrition science of the century, says the study’s senior author, Scott Small, MD, the Boris and Rose Katz Professor of Neurology at Columbia University’s Vagelos College of Physicians and Surgeons, in a university release.

In this century, as we live longer, research is beginning to reveal that several nutrients are needed to fortify our aging minds. Our study, which is based on biomarkers of flavanol consumption, can be used as a model by other researchers to identify additional required nutrients.

Scroll down to see all foods high in flavanols

The study builds on more than 15 years of research by the same team showing that flavanols improve heart function. Toothed turn, a part of the brain’s hippocampus that is vital for learning and forming new memories. Further experiments in mice found that a bioactive substance in flavanols called epicatechin boosts memory by improving the growth of neurons and blood vessels.

In the latest research, more than 3,500 healthy older adults were randomly assigned to receive a daily supplement or placebo for three years. The active pill contained 500 mg of flavanols, including 80 mg of epicatechins, a dosage that adults are recommended to get from their diet. After the first year of supplementation, participants who ate a poorer diet and had lower levels of flavanols saw their memory scores increase by an average of 10.5% compared to those who took the placebo and by 16% compared to their baseline memory score.

Yearly cognitive tests showed that the improvements seen after one year persisted for at least another two years. The findings strongly suggest that a flavanol deficiency contributes to age-related memory loss, according to the researchers. Flavanol consumption was correlated with memory scores, and flavanol supplements improved memory in flavanol-deficient adults.

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At the start of the study, all participants completed a survey to rate the quality of their diets, including foods known to be high in flavanols. They also undertook a series of in-home web-based tasks, designed and validated by Brickman, to assess the types of short-term memory governed by the hippocampus. These tests were repeated after years one, two and three.

Over a third of the participants also provided urine samples, allowing the researchers to measure a biomarker for dietary flavanol levels, both before and during the study. Memory scores improved only slightly for the entire group taking the daily flavanol supplement, most of whom were already consuming a flavanol-rich diet.

These results are in line with a recent study that found that flavanol supplements did not significantly improve memory in a group with a variety of baseline flavanol levels. However, this previous study did not separately look at the effects of flavanol supplements on people with low and high flavanol levels.

What both studies show is that flavanols have no effect on people who don’t have a flavanol deficiency, says Small.

Furthermore, it is possible that the memory tests employed in the previous study did not effectively assess memory processes in the flavanol-influenced area of ​​the hippocampus.

In the present study, flavanols only improve hippocampal-governed memory processes and do not improve memory mediated by other brain areas.

We can’t yet conclusively conclude that low dietary intake of flavanols alone causes poor memory performance, because we haven’t conducted the opposite experiment: depleting flavanols in people who aren’t deficient, says Small, adding that such an experiment could be considered unethical.

The next step in this research is a clinical study aimed at restoring flavanol levels in adults with severe flavanol deficiency.

Age-related memory decline is thought to occur sooner or later in nearly everyone, though there’s a lot of variability, Small says. If some of this variance is in part due to differences in dietary flavanol consumption, then we would see even more dramatic improvement in memory in people who replenish dietary flavanols in their 40s and 50s.

The team’s findings are published in the journal Proceedings of the National Academy of Sciences.

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South West News Service writer Mark Waghorn contributed to this report.