Consuming berries could delay brain aging up to two and a half years

Friday, April 27, 2012. An article published online on April 26, 2012 in the Annals of Neurology reports a protective effect for diets containing high amounts of blueberries and strawberries against cognitive decline in older women. Berries are high in compounds known as flavonoids, which may help reduce the negative impact of inflammation and stress on cognitive function.

"As the U.S. population ages, understanding the health issues facing this group becomes increasingly important," commented lead researcher Elizabeth Devore of Brigham and Women's Hospital and Harvard Medical School. "Our study examined whether greater intake of berries could slow rates of cognitive decline."

Dr Devore and her associates evaluated data from women who were between the ages of 30 and 55 upon enrollment in the Nurses' Health Study in 1976. Dietary questionnaires completed every four years since 1980 were analyzed for the frequency of berry intake as well as the intake of 31 individual flavonoids representing six major flavonoid subclasses commonly found in US diets. Cognitive function was tested every two years in 16,010 participants who were over the age of 70 between 1995 and 2001.

Consuming a relatively high amount of blueberries or strawberries was associated with a slower decline in cognitive function test scores over the follow-up period compared to women whose intake was lower, resulting in a delay in cognitive aging of up to 2.5 years. Greater intake of the anthocyanidin class of flavonoids and total flavonoids was also associated with a reduced rate of decline.

"Substantial biologic evidence supports our finding that berry and flavonoid intake may be related to cognition," the authors write. "Berry-derived anthocyanidins are uniquely and specifically capable of both crossing the blood–brain barrier and localizing in brain regions involved in learning and memory (eg, the hippocampus). In multiple studies of rats, blueberry or strawberry supplementation significantly reduced age-related declines in neuronal signaling and cognitive behavior, and supplementation at older ages reversed neuronal and cognitive decline."

"We provide the first epidemiologic evidence that berries may slow progression of cognitive decline in elderly women," Dr Devore announced. "Our findings have significant public health implications as increasing berry intake is a fairly simple dietary modification to test cognition protection in older adults."