The study, published in the British Journal of Nutrition, included 12 older adults with memory decline (not dementia). They were randomly assigned to receive either 100% Concord grape juice or placebo three times per day for 12 weeks. The total amount of juice consumed per day was based on each person’s body weight (between 444 and 621 ml; 14 and 21 ounces).
The people receiving grape juice did up to 60% better at the end of the study compared to the beginning on tests that measured learning and memory, while those receiving the placebo drink showed no improvement. Average body weight and waist circumference did not change in either group.
Anthocyanins are reddish-blue flavonoid pigments abundant in fruits such as purple grapes and blueberries, and vegetables such as purple cabbage. They are in the family of polyphenols known as flavonoids, which are powerful antioxidants. The authors of this study speculated that the anthocyanins and other polyphenols found in Concord grape juice might be responsible for the benefits they saw.
“Given the existing body of research linking polyphenol consumption with a lower risk of age-related neurodegenerative changes and with reduced levels of inflammatory and oxidative stress markers in people with cardiovascular disease, it is likely that the flavonoids found in Concord grape juice are at least partly responsible for the beneficial effects we observed,” said lead study author Dr. Robert Krikorian from the University of Cincinnati Academic Health Center.
Drinking grape juice is a good way to increase your levels of anthocyanins. Eating anthocyanin-rich foods is safe, so pile your plate high with purple grapes, blueberries, and purple cabbage. Other ways to prevent cognitive decline include the following:
(Br J Nutr 2010;103:730–4)