A Harvard study published in the Annals of Neurology indicates that eating a diet high in blueberries and strawberries can slow brain aging and cognitive decline by up to two and a half years.
Dr. Elizabeth Devore and her team of researchers at Harvard Medical School analyzed data from the lengthy Nurses’ Health Study in 1976. Questionnaires were completed every four years since 1980 to assess the frequency of berry intake and the intake of 31 different phytonutrients called flavonoids. In 16,010 participants over the age of 70 between 1995 and 2001, cognitive function was tested every two years.
The researchers found that those participants who consumed a high amount of blueberries or strawberries had slower decline in cognitive function test scores during the follow-up period than those whose intake of these fruits was lower. The results were an average delay in cognitive decline due to aging of up to 2-and-a-half years.
Both blueberries and strawberries are excellent sources of flavonoids, which reduce inflammation. This is possibly the mechanism that is causing the positive brain health effects. The same study also found that a high intake of anthocyanidins and total flavonoids were also linked to the beneficial cognitive effects.
Anthocyanidins are a type of flavonoids responsible for the red, blue, or purple colors in berries and other foods. While the effect of consumption of other anthocyanidin and flavonoid-rich foods was not assessed as part of this study, it is likely that they will have similar brain protective effects. Other sources of anthocyanidins and flavonoids include: blueberries, cherries, cranberries, grapes, raspberries, and strawberries and to a lesser extent in almonds, apples, cocoa, and peanuts.
Other research shows that they decrease free radical activity in and between brain cells. They also inhibit the production of histamine, making them a natural anti-histamine without the drowsy side effects of many pharmaceuticals. Numerous studies show that anthocyanidins have anticancer and antitumor activity, and one study concluded that anthocyanidins may demonstrate chemotherapeutic activity against breast cancer.
When it comes to heart disease, anthocyanidins help reduce high blood pressure and improve the body’s ability to metabolize fat. In tests on rabbits, anthocyanidins demonstrated significant reduction in the development of atherosclerosis. They also appeared to protect against heart attacks linked to certain asthma drugs. They even have stronger antioxidant properties than either vitamins C or E.