As we age, we suffer from memory loss because the passing of the years also affects cognitive functions. Our lifestyle can positively or negatively influence the health of the body and brain, and a large study has shown for the first time that a diet low in flavanols, a type of flavonoids (natural antioxidant substances found in some fruits and vegetables, tea, apples, cocoa or berries) contributes to memory loss.
The research has been carried out by scientists from Columbia University Irving Medical Center and Brigham and Women’s Hospital/Harvard and has also found that the intake of flavonoids in adults older than 60 who had a mild deficiency of these nutrients improved their performance in tests designed to detect age-related memory loss.
“The improvement among study participants on low-flavonoid diets was substantial and raises the possibility of using flavonoid-rich diets or supplements to improve cognitive function in older adults,” said Adam M. Brickman, a professor of neuropsychology at the College of Vagelos of Physicians and Surgeons at Columbia University and co-director of the study.
“As we live longer, research is beginning to reveal that different nutrients are needed to strengthen our aging minds”
The results of the work have been published in The American Journal of Clinical Nutrition and support the idea that the aging brain needs a series of specific nutrients to maintain good health, just like the brain of a baby or child still is developing needs certain nutrients to do so.
“The identification of nutrients critical to the proper development of an infant’s nervous system was a crowning achievement of 20th-century nutrition science,” said Scott A. Small, MD, lead study author and Boris and Rose Professor Katz Professor of Neurology at Columbia University’s Vagelos College of Physicians and Surgeons, adding: “In this century, as we live longer, research is beginning to reveal that different nutrients are needed to strengthen our aging minds. Our study, which is based on biomarkers of flavonoid intake, can be used as a model by other researchers to identify additional needed nutrients.”
Changes in the hippocampus linked to memory loss
The new research builds on studies that have been conducted in Dr. Small’s lab for more than 15 years linking age-associated memory loss to changes in the dentate gyrus, an area within the hippocampus of the brain – a key region for storing new memories – and shows that flavanols improve function in this region of the brain.
Researchers found in tests on mice that flavanols, especially a bioactive substance called epicatechin, improve memory by increasing the growth of neurons and blood vessels in the hippocampus. Small’s team then tested flavanol supplements in people.
They selected 3,562 healthy older adults who were divided into groups to receive either a flavanol-supplemented pill (with cocoa extract) or a placebo pill every day for three years. The active supplement contained 500 mg of cocoa-derived flavanols, including 80 mg of epicatechins, which is the recommended daily amount for adults to obtain from food.
All participants responded to a questionnaire at the start of the study assessing the quality of their diet, including foods high in flavanols. They then completed a series of activities in their own homes, designed and validated by Brickman, to assess the types of short-term memory controlled by the hippocampus. The tests were repeated after years one, two, and three.
Urine samples were also collected from more than a third of the participants which allowed the researchers to measure a biomarker for dietary flavonoid levels, before and during the study, and provided them with a more accurate way of determining if flavonoid levels flavonoids were correlated with performance on cognitive tests.
Memory scores improved slightly for everyone taking the daily flavonoid supplement, most of whom already ate a healthy diet high in flavonols. But after one year taking the flavanol supplement, the memory scores of participants with a poorer diet and lower baseline levels of flavanols increased by an average of 10.5% compared with those in the placebo group, and 16%. compared to his memory at the beginning. Annual cognitive tests showed that the improvement observed at one year was sustained for at least two more years.
In the investigators’ opinion, the results support that flavanol deficiency is a driver of age-related memory loss, because flavanol intake was correlated with memory scores and flavanol supplementation improved memory in adults with flavanol deficiency. “Age-related memory decline is thought to occur sooner or later in almost everyone, although there is great variability,” says Small. “If some of this variation is due in part to differences in dietary flavanol intake, then we would see an even more dramatic improvement in memory in people who replenish dietary flavanols in their 40s and 50s,” she concludes.
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