By now, it's no secret that berries are good for us.
But can they actually help keep your brain sharp as you age?
A study released by researchers at Boston's Brigham and Women's Hospital (BWH) indicates that diets rich in berries can delay memory decline in older women by 2-1/2 years.
“What makes our study unique is the amount of data we analyzed over such a long period of time. No other berry study has been conducted on such a large scale,” explained lead author Elizabeth Devore.
“Among women who consumed two or more servings of strawberries and blueberries each week, we saw a modest reduction in memory decline.”
The evidence from several epidemiological and clinical studies has been mixed but generally positive, while animal studies consistently show brain benefits from diets rich in berries.
And a similar study by Brigham and Women's Hospital researchers detected possible memory benefits from diets high in vegetables (Kang JH et al. 2005).
Biggest study to date examined data from nurses
The research team used data from the Nurses' Health Study – which involved 121,700 female registered nurses between the ages of 30 and 55 – who completed health and lifestyle questionnaires beginning in 1976.
Starting in 1980, participants have been surveyed every four years to determine their dietary habits.
Between 1995 and 2001, memory was measured in 16,010 participants over the age of 70 years, at two-year intervals.
The women's average age was 74 and their average body mass index was a relatively healthy 26.
Berry-rich diets linked to delayed memory decline
The Boston team's findings linked higher consumption of blueberries and strawberries to a slower rate of memory decline (Devore EE et al. 2012).
And the researchers linked higher intakes of certain food-borne “antioxidants” – total flavonoids and the flavonoids known as anthocyanidins – with reduced memory decline.
Berries rank among the richest sources of anthocyanidins and other flavonoids.
They found that women who had higher berry intakes than average delayed any memory decline by up to 2-1/2 years.
“We provide the first epidemiologic evidence that berries appear to slow progression of memory decline in elderly women,” said Dr. Devore.
And she stressed a key point: “Our findings have significant public health implications as increasing berry intake is a fairly simple dietary modification to reduce memory decline in older adults.”
This study was funded by grants from the National Institutes of Health and the California Strawberry Commission, and was independently controlled by the investigators.
Devore EE, Kang JH, Breteler MM, Grodstein F. Dietary intakes of berries and flavonoids in relation to cognitive decline. Ann Neurol. 2012 Apr 26. doi: 10.1002/ana.23594. [Epub ahead of print]
Devore EE, Kang JH, Stampfer MJ, Grodstein F. Total antioxidant capacity of diet in relation to cognitive function and decline. Am J Clin Nutr. 2010 Nov;92(5):1157-64. Epub 2010 Sep 8.
Kang JH, Ascherio A, Grodstein F. Fruit and vegetable consumption and cognitive decline in aging women. Ann Neurol. 2005 May;57(5):713-20.