Age-Related Memory Loss Could Be Averted With Tea, Apples, and Berries, Study Suggests
Results of a recent study show that with every sip of green tea and every bite of apples and berries, older adults may be protecting themselves against age-related memory loss.
Researchers at Columbia University and Brigham and Women’s Hospital/Harvard found that study participants who consumed higher levels of flavanols had better short-term memory than those who consumed a diet low in flavanols.
Dr. Scott Small, the study’s senior author and professor of neurology at Columbia University, told The Guardian that the findings contribute to a growing body of research that shows “different nutrients are needed to fortify our aging minds.”
Flavanols are compounds with antioxidant properties and contain nutrients. Flavanols are naturally found in many fruits, vegetables, tea, and cocoa. The Academy of Nutrition and Dietetics recommends consuming 400 to 600 milligrams (mg) of flavanols a day. There is also evidence that shows increasing consumption of dietary flavanols can help improve blood pressure, cholesterol concentrations, and blood sugar.
According to the U.S. Department of Agriculture, some of the fruits and vegetables that are high in flavanols include:
- Hot peppers
When it comes to teas, studies have found green, oolong, and black teas have high amounts of dietary flavanols.
The three-year dietary flavanols study, published in Proceedings of the National Academy of Sciences journal in May, involved 3,562 people who were around 71 years old. Participants were randomly assigned a daily supplement of 500 mg of flavanols in pill form or a placebo pill. At the beginning of the study, participants were given a survey about their diets and took several short-term memory tests online each year. Also, more than a third of participants gave urine samples so that researchers could measure dietary flavanols levels.
The investigators found that the memory scores of the group that took the flavanol pill only improved slightly. However, a subset of participants within this group who had poor diet and flavanol consumption at the beginning of the study saw their memory scores increase by an average of 10.5 percent compared with the placebo group, and by 16 percent compared with the start of the study.
Research team members said participants who did not have a flavanols deficiency were not affected by the flavanol supplements. However, the researchers believe supplements can help reverse memory loss in people who do not consume enough flavanols in their daily diets.
“The improvement among study participants with low-flavanols diets was substantial and raises the possibility of using flavanol-rich diets or supplements to improve cognitive function in older adults,” Adam M. Brickman, a professor of neuropsychology at Columbia University Vagelos College of Physicians and Surgeons and co-leader of the study, said in a news release about the study.
Although the daily recommendation of flavanols ranges between 400 to 600 mg, Gunter Kuhnle, a co-investigator of the study and a professor of nutrition and food science at the University of Reading, told The Guardian the results suggest the optimum amount of flavanols is a daily intake of about 500 mg.
Prof. Aedin Cassidy, chair in nutrition and preventative medicine at Queen’s University Belfast, told The Guardian this is a “really important study” because the amount of flavanols required to improve brain health is “readily achievable.”
“For example, one mug of tea, six squares of dark chocolate, a couple of servings of berries and apples would together provide about 500 mg of flavanols,” Cassidy said.
Although the study used 500 mg of flavanols extracted from dark cocoa, researchers caution against trying to get the same results by consuming 500 mg of chocolate. Kuhnle said the extraction process for the study was intensely “optimized” in the lab.
“The best way to meet 500 milligrams a day is by consuming a range of different flavanol-containing foods,” Kuhnle told CNN Health.
Study Receives Mixed Reviews
Some researchers who weighed in on the flavanol study were not too impressed with the results. For example, one aspect of the study focused on remembering words. By the end of the third year of the study, participants who had the lowest level of flavanols at the beginning of the study and then took the cocoa supplement remembered 7.94 words out of 20 words, compared to 7.63 words in the placebo group.
According to Dr. Jeffrey Linder, chief of general internal medicine at Northwestern University’s Feinberg School of Medicine in Chicago, the small difference was not significant.
“Within the low diet quality group, there was a significant trend in increasing word recall in the flavanol group relative to the placebo group, but there were no individual year significant differences,” Dr. Linder, who was not involved in the study, told CNN Health.
On the other hand, Dr. Ian Johnson, an emeritus fellow at the Quadram Institute in Norwich, a center for food and health research in the United Kingdom, described the study as “large and rigorously conducted” research.
In fact, Dr. Johnson, who was not involved in the study, told The Guardian that the study added to previous research that showed “the importance of diet as a factor supporting cognitive health in later life.” Dr. Johnson, however, believed that more in-depth studies were probably needed to examine the benefits of flavanol supplements.
Carl Hodgetts, senior lecturer in cognitive neuroscience at Royal Holloway, University of London, told The Guardian that further research into how nutrition affects the brain could be beneficial in the fight against dementia.
Investigators at Columbia and Brigham and Women’s Hospital/Harvard said they could not definitively conclude that low dietary intake of flavanols alone causes poor memory performance. So, they plan to conduct a clinical trial to restore flavanols levels in adults who are deficient.
“Age-related memory decline is thought to occur sooner or later in nearly everyone, though there is a great amount of variability,” Dr. Small said in the news release.