Key Points:
- Older adults with poor-quality diets who consume 500 mg of cocoa extract see a progressive improvement in memory over 3 years.
- Cocoa supplementation improves memory scores for those with low flavanol intake.
- Supplementation with cocoa extract restores flavanol intake to average levels.
Flavanols are food constituents in certain fruits and vegetables, including tea, apples, berries, grapes, and cocoa. Smaller studies have shown that consuming flavanols, which have an effect on new blood vessel formation, improves memory. Now, researchers from Columbia University have replicated similar results in a much larger study.
As reported in PNAS, Brickman and colleagues show that older individuals with poor-quality diets who consume 500 mg/day of cocoa extract — rich in flavanols — have better memory scores over three years. Additionally, individuals with low flavanol intake see a normalization of flavanol intake after cocoa supplementation and memory improvements after a year.
Cocoa Supplementation Improves Memory in Flavanol-Deficient Older Adults
Brickman and colleagues randomly assigned 3,562 older adults to a 3-year intervention of 500 mg/day cocoa extract or placebo. Within the cocoa or placebo group, the participants were divided based on the quality of their diet. Diet quality was assessed using the alternative healthy eating index (AHEI). High AHEI scores are associated with a 19% lower risk of chronic disease and a 25% lower risk of dying from any cause.
Participants who scored lowest on the AHEI had the poorest memory scores, evaluated using the modified Rey auditory verbal learning (ModRey) test. However, after a year of cocoa supplementation, these individuals saw improvements in the ModRey score that continued to improve after two and three years. These findings demonstrate that cocoa supplementation improves the memory of older individuals with poor-quality diets.
A low AHEI score should correlate with less flavanol intake. However, while self-reported consumption of supplements or foods is the go-to for many studies, Brickman and colleagues used an objective measurement to assess this flavanol intake. They developed a urine-based biomarker involving a flavanol metabolite called 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone (gVLM). Of all the participants, 1,361 provided urine samples for analyzing gVLM levels.
Similar to the AHEI scores, the researchers divided the participants based on their gVLM levels. It was found that low-gVLM-participants who consumed cocoa had better ModRey memory scores than low-gVLM-participants in the placebo group. These findings indicate that cocoa supplementation can improve the memory of older individuals with low flavanol intake.
To gain a better understanding of how cocoa supplementation improves flavanol intake levels, Brickman and colleagues took gVLM data from a previous study of over 6,000 older adults. They used this data to generate a distribution curve and determine an average gVLM level for older adults. This curve and average were used as a reference population.
Compared to the reference population, low-gVLM-participants were found to have below average gVLM levels. However, after one year of cocoa supplementation, their gVLM levels increased and reached average levels. These findings indicate that one year of cocoa supplementation restores flavanol intake to normal levels for older adults with low flavanol intake.
Overall, the findings of Brickman and colleagues suggest that supplementing with 500 mg/day of cocoa extract can improve the memory of older adults with low habitual flavanol intake. Side-effects of cocoa supplementation included nausea and stomach discomfort in some participants. However, participants who consumed cocoa were also slightly less likely to have flu-like symptoms. The authors state:
“We are not only living longer, but we are living cognitively more demanding lives. Our findings suggest that flavanol consumption might be considered in future dietary recommendations, perhaps together with the flavanol biomarker, specifically geared toward preventing or improving brain health in later life.”
How Much Chocolate is Needed to Get 500 mg of Cocoa Flavanols?
“Age-related memory decline is thought to occur sooner or later in nearly everyone, though there is a great amount of variability,” says Dr. Scott A. Small, the principal investigator of the study. “If some of this variance is partly due to differences in dietary consumption of flavanols, then we would see an even more dramatic improvement in memory in people who replenish dietary flavanols when they’re in their 40s and 50s.”
What Dr. Small is alluding to is that we have the potential to prevent age-related memory loss if we make sure we have adequate flavanol intake throughout our lifespan. While a generally healthy diet may provide sufficient flavanols, it may be beneficial to consume cocoa or other flavanol-rich foods to make sure. This is considering the difficulty in getting biomarkers like gVLM measurements to assess our flavanol intake. Furthermore, some flavanols have a similar structure to senolytics like quercetin and fisetin, suggesting that they have global anti-aging effects.
Cocoa is available in many forms, including an extract form like the one used in this study. A cocoa extract should provide the highest concentration of flavanols. Another option is unsweetened cocoa powder, which can have 37 to 130 mg of cocoa flavanols per serving, according to Consumer Lab. Another form, unsweetened baking chocolate, can have up to 592 mg of flavanols.
Of course, 100% cocoa has a bitter taste, so milk and sugar are usually added. A sweetened dark chocolate bar can have between 136 mg to 440 mg of flavanols, while a milk chocolate bar of the same size may contain 30 mg of flavanols. In this case, it would take over 15 milk chocolate bars (containing around 255 grams of sugar) to get 500 mg of cocoa flavanols. Therefore, dark chocolate appears to be the best option when it comes to maximizing flavanol content and minimizing sugar intake.
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