Frequent consumption of berries can slow memory loss, suggests a new US study.
Women with the highest consumption of blueberries or strawberries showed about 1.5 to 2.5 years of delay mental aging, such as loss of memory and reasoning abilities.
For the study, published Thursday in the Annals of Neurology, the researchers measured mental function in 16,010 women using telephone interviews about every two years they have lived in for six years.
"We present the first epidemiologic evidence that berries can slow the progression of mental decline in older women," said study author Dr. Elizabeth Devore of Brigham and Women's Hospital and Harvard Medical School in Boston.
Women who ate the most fruits, eat half a cup of blueberries and a cup of strawberries a week. Women with the highest intake of berries also tend to have higher levels of physical activity compared to those who ate the least amount of berries. Factors such as education and smoking were taken into account in the analysis.
Other experimental evidence from a small number of elderly people and some animals also indicate the benefit of berries for mental development, the researchers say.
However, scientists say that, rather than to focus on some berries, people should consume a wide range of fruits and vegetables, which contain flavonoids - along with vitamins C, E and beta-carotene, have antioxidant properties and protect the body against free radicals.
"The most remarkable advice is to eat a wide range of flavonoids, rather than large amounts of certain fruits, as the excessive use of some vegetables is problematic and sometimes harmful," says Somerset from the Australian Broadcasting Corporation. "This requires the use of a range of fruits and vegetables, not just one type of fruit».
The researchers recognized that there were limitations in the study, such as dietary information, which is not reported by the subjects. The results may not apply to men, although few studies have found significant sex differences in dietary risk factors for dementia and mental decline in men.
The study was funded by the US National Institutes of Health, the National Cancer Institute and the California Strawberry Commission.