An international team of researchers has found that a high intake of flavonoid-rich berries, such as strawberries and blueberries, over time, can delay memory decline in older women by 2.5 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,” said Dr. Elizabeth Devore, a researcher at Brigham and Women’s Hospital in Boston and a lead author of the study.
The team used data from the Nurses’ Health Study – a cohort of 121,700 female, registered nurses between the ages of 30 and 55 – who completed health and lifestyle questionnaires beginning in 1976. Since 1980, participants were surveyed every four years regarding their frequency of food consumption. Between 1995 and 2001, memory was measured in 16,010 subjects over the age of 70 years, at 2-year intervals. Women included in the present study had a mean age of 74 and mean body mass index of 26.
The findings, published in the journal Annals of Neurology, show that increased consumption of blueberries and strawberries was associated with a slower rate of memory decline in older women.
“Among women who consumed 2 or more servings of strawberries and blueberries each week we saw a modest reduction in memory decline,” Dr. Devore explained. “This effect appears to be attainable with relatively simple dietary modifications.”
A greater intake of anthocyanidins and total flavonoids was also associated with reduced memory decline. Flavonoids are compounds found in plants that have powerful antioxidant and anti-inflammatory properties. Researchers believe that stress and inflammation contribute to cognitive impairment and that increasing consumption of flavonoids could mitigate the harmful effects.
The results show that women who had higher berry intake had delayed memory decline by up to 2.5 years.
“We provide the first epidemiologic evidence that berries appear to slow progression of memory decline in elderly women,” Dr. Devore concluded. “Our findings have significant public health implications as increasing berry intake is a fairly simple dietary modification to reduce memory decline in older adults.”