Are You Getting Enough Flavanols?
A diet deficient in these naturally occurring compounds can lead to age-related memory loss.
Could consuming something as simple as flavanols—naturally occurring antioxidants present in foods such as green tea, apple peels, strawberries, dark chocolate, and cocoa—prevent cognitive decline as we age? According to a study published last week in the journal PNAS, the answer may be yes!
Researchers from Columbia University in New York collaborated with researchers at Brigham and Women’s Hospital in Boston and the University of Reading in the United Kingdom to study the effects of flavanols and multivitamins as an ancillary part of a larger study called COSMOS (COcoa Supplements and Multivitamin Outcomes Study), which was funded in part by Mars Edge, a nutrition-focused initiative within Mars, Incorporated, the National Institutes of Health, and the Nathaniel Wharton Fund. The goal of the study was to examine whether dietary flavanol improved memory function in older adults and whether this memory improvement was restricted to those with lower flavanol levels.
The researchers looked at the impact of adding 500mg a day of flavanols to your diet—about the equivalent of consuming in a single day one cup of tea, an apple, an orange, a large handful of blueberries, and a few pieces of broccoli. They found the flavanols may slow age-related mental declines among people with relatively lower flavanol levels or poorer diets. Their study suggests that flavanols maintain hippocampal memory and cognitive performance during normal cognitive aging and that a diet low in flavanols can result in age-related memory loss.
Their findings are in line with other studies, including a study published in the journal Scientific Reports that found that drinking cocoa with high levels of flavanols increased blood oxygenation in the brain and improved performance on a complex cognitive task. Another study published last year in the journal Neurology found that people who ate or drank more foods with flavanols had a slower rate of memory decline.
“The flavanol supplements had no effect on people who did not have a flavanol deficiency.”
For this current study, 3,500 healthy adults (average age 71) were randomly assigned to receive either a daily 500mg flavanol supplement or a placebo pill for three years. The participants took several memory tests during the study period and filled in surveys that assessed their diet. Although memory scores improved only slightly for the group taking the flavanol pill, those who had poor diet and low flavanol consumption at the beginning of the study showed bigger improvements in memory. Their memory scores increased by an average of 10.5 percent compared to placebo and 16 percent when compared to their memory at baseline. The flavanol supplements improved memory only in flavanol-deficient adults. They had no effect on people who did not have a flavanol deficiency.
Adam M. Brickman of Columbia University, who co-led the study, says that by using a biomarker to measure flavanol levels in people, the study team was able to confirm that lower flavanol levels were associated with poorer memory. They showed that correcting relatively low flavanol levels improved memory in a dose-response fashion—the degree of increase in flavanol levels with diet was related to the degree of improvements in memory. “Together the findings suggest, perhaps, that a flavanol deficiency in older adults may be one source of age-related memory decline,” Brickman says.
Diet and the aging brain
The study is the culmination of 15 years of research in both mice and humans that provides biomarker-based evidence that dietary consumption of flavanols is linked to age-related cognitive decline. According to Columbia University neurologist Scott Small, the senior author on the new PNAS paper, the work highlights how important brain health is later in life.
“We know that in children, specific nutrients are needed for proper development,” he says. “Our findings support the idea that the aging brain also requires nutrients for optimal health and that flavanols seem to benefit the dentate gyrus, an area within the brain’s hippocampus that is critical to memory.”
Brickman says it’s important to keep in mind that the study was not about treating or preventing Alzheimer’s disease. Rather, its focus was on normal age-related memory changes. “We do not believe that flavanol intake is an approach for prevention of Alzheimer’s disease or other neurodegenerative conditions,” he says.
Hagen Schroeter, chief science officer at Mars Edge, and Javier Ottaviani, the director of the company’s core laboratory, were both co-authors of the study and contributed to its methodology, including the development of a biomarker analysis tool for measuring the baseline dietary flavanol intake of the study participants. (The authors from Mars Edge did not have a role in the statistical analysis.)
Mars markets CocoaVia, a dietary supplement made with the company’s own cocoa extract—Cocoapro, which they claim is the “most concentrated source of cocoa flavanols on the market.” Each CocoaVia supplement provides 500mg-750mg of cocoa flavanols per serving. (The daily dietary amount of flavanols recommended by the Academy of Nutrition and Dietetics is 500mg, and the academy notes that flavanol supplements are known to cause gastrointestinal irritation and liver injury, “particularly when taken in excess or on an empty stomach.”)
Schroeter’s interest in cocoa flavanols goes back more than two decades. He notes that it started from the company’s flavor research program, where these compounds were identified as contributors to the taste and flavor characteristics in cocoa. Among their accomplishments were partnering with the National Institute of Standards and Technology to implement analytical standards for consistent and reliable cocoa flavanol reporting (using radiocarbon labeling to understand how flavanols are metabolized) and partnering with the Brigham and Women’s Hospital on the COSMOS study. Mars Edge is also a member of the EU-funded FLAVIOLA project that investigated the impact of flavanol consumption in the EU and developed cocoa flavanol (CF)-rich food product prototypes.
“Even if an individual is not willing to modify and overhaul their diet, they can still take steps to ensure they are getting an appropriate amount of vitamins, minerals, and bioactives.”
Proto.life asked Thomas M. Holland, a physician and scientist at Rush Medical College in Chicago who was not involved with the study, for comments. “The amazing thing about this manuscript,” says Holland, referring to the new study, “is that it gives a bit more hope in terms of bridging the gap between poor nutritional status and nutrients or bioactives that are important for brain health.”
“The work shows that even if an individual is not willing to modify and overhaul their diet, they can still take steps to ensure they are getting an appropriate amount of vitamins, minerals, and bioactives. This can potentially help maintain their cognitive ability,” Holland says.
He added, “The study findings bridge the gap between a poor diet and maintaining brain health, and [it] has possible implications for individuals that have difficulty swallowing or other disease processes that can impede digestion of foodstuffs and subsequent absorption of those nutrients and bioactives.”
Editor's note: This story was updated on 6/12/23 to reflect that CocoaVia supplements provide 500mg-750mg of flavanols per serving.