Scientists have found that consuming fruits rich in flavonoids such as blueberries and strawberries may delay cognitive decline in older women by up to 2.5 years.
Flavonoids are compounds found in plants that typically have powerful antioxidant and anti-inflammatory properties. Researchers believe the consumption of flavonoids can reduce the cellular stress and inflammation that causes cognitive decline.
Previous studies of the positive effects of flavonoids, particularly anthocyanidins, have been limited to animal models or very small trials in older persons. Nevertheless, these trials have shown that greater consumption of foods with these compounds improve cognitive function.
The current study is published in the Annals of Neurology, a journal of the American Neurological Association and Child Neurology Society.
Dementia or cognitive decline is expected to be a serious public health issue as the population of Americans 65 years of age and older expands. This population has grown faster than the total U.S. population for the decade 2000-2010 — before the leading edge of the baby boomers generation reached 65 in 2011.
“As the U.S. population ages, understanding the health issues facing this group becomes increasingly important,” said Dr. Elizabeth Devore with Brigham and Women’s Hospital and Harvard Medical School in Boston, Mass. “Our study examined whether greater intake of berries could slow rates of cognitive decline.”
Researchers used data from the Nurses’ Health Study — a group 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, cognitive function 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.
Researchers discovered that increased consumption of blueberries and strawberries appear to slow cognitive decline in older women. A greater intake of anthocyanidins and total flavonoids was also associated with reduce cognitive degeneration.
Investigators do provide the caveat that although they controlled for other health factors in the modeling, they cannot rule out the possibility that the preserved cognition in those who eat more berries may be also influenced by other lifestyle choices, such as exercising more.
“We provide the first epidemiologic evidence that berries may slow progression of cognitive decline in elderly women,” noted Devore. “Our findings have significant public health implications as increasing berry intake is a fairly simple dietary modification to test cognition protection in older adults.”