If you don’t eat a lot of foods with flavanols — a kind of antioxidant found in certain fruits, veggies, tea, and cocoa — a daily flavanol supplement might help stall or even reverse age-related memory loss, a new study suggests.
For the study, researchers randomly assigned more than 3,500 older adults to take either a daily flavanol supplement or a placebo pill for three years. The supplement contained 500 milligrams (mg) of flavanols extracted from cocoa, which was within the 400 to 600 mg range recommended by the Academy of Nutrition and Dietetics as part of a healthy diet.
When they joined the study, and annually during the follow-up period, participants completed a series of short-term memory tests designed to measure subtle changes in skills like word recall that tend to erode with advanced age. They also completed diet surveys that assessed the overall healthiness of foods they consumed and how often they ate foods known to be rich in flavanols.
The Biggest Memory Benefit Was for People With Low-Antioxidant Diets
Overall, the impact of flavanols on memory appeared modest, and the improvements after one year for people taking supplements were too small to rule out the possibility that they were due to chance, researchers reported May 30 in the Proceedings of the National Academy of Sciences (PNAS). Most of the study participants had fairly healthy diets and already ate a lot of foods rich in flavanols.
But for the people who had the lowest-quality diets and consumed the fewest flavanol-rich foods, supplements made a significant difference. For this subset of participants, memory test scores were 16 percent higher after one year of taking flavanol supplements than they were at the start of the study.
“Memory was worse in those participants who had lower than normal flavanols, and memory was restored when their flavanols were restored to normal levels,” says a coauthor of the study, Scott A. Small, MD, a neurology professor and the director of the Alzheimer’s Disease Research Center at Columbia University in New York City.
Antioxidant Deficiency May Be Tied to Age-Related Memory Loss
What this suggests is that flavanol deficiency might be one driver of age-related cognitive decline, Dr. Small says. “Anyone with a deficiency in flavanols might benefit from consuming more flavanols,” he says.
One limitation of the study is that most participants ate fairly well, the researchers noted. It’s possible that the impact of increased flavanol consumption on memory would be more dramatic if scientists focused only on people who had the poorest-quality diets, with few sources of flavanols, such as whole fruits and vegetables.
It would also be a mistake to start eating 500 mg of chocolate a day in hopes of boosting memory or avoiding age-related cognitive decline. That’s because the supplements in the study were made from concentrated cocoa extract, and were free of the sugars and fats found in most chocolate bars.
The study was funded in part by the chocolate manufacturer Mars.
Flavanols Can Be Found in Many Fruits and Vegetables
Flavanols from any healthy source could have at least some of the impact of the cocoa flavanol supplements people took in the study, Small says. “There are many fruits and vegetables that contain flavanols, and that would be our recommendation,” Small says.
More broadly, the study suggests that a diet rich in flavanols and other phytonutrients — plant nutrients with antioxidant, anti-inflammatory, and disease-fighting properties — can help keep the body and brain healthy, says Samantha Heller, RD, a senior clinical nutritionist at New York University Health in New York City who wasn’t involved in the new study.
“Including foods such as colorful vegetables and fruits, legumes, whole grains, nuts, and seeds in one’s diet has been shown to decrease the risk of many chronic diseases and cognitive decline,” Heller says. “While cocoa contains many phytochemicals, consuming a variety of plant foods helps ensure that we are getting the wide array of these nutrients.”
