As baby boomers grow older, cognitive decline has become one of America’s most critical medical issues. The popularity of blueberries and other fruits rich in flavonoids has also been rising. The first long term study investigating the effects of flavenoids on the brain confirms that eating berries can delay the onset of cognitive aging.
Baby boomers and blueberries
Compared to an overall population increase of 9.7 percent, the number of people reaching at least 65 years old in the U.S. rose by 15 percent from 2000-2010, according to the 2010 U.S. Census. In the search for ways to reduce dementia risk, numerous studies have shown that eating sources of antioxidants called flavenoids, such as blueberries and strawberries, can improve cognitive function.
Previous research had its limits because the studies used animals or very small human samples. For the new study, researchers from Brigham and Women’s Hospital and Harvard Medical School analyzed data from the long-term Nurses’ Health Study of nearly 122,000 registered nurses between the ages of 30 and 55.
Cognitive aging delayed 2.5 years
Participants completed health questionnaires starting in 1976. Every four years the nurses were surveyed on their eating habits. From 1995 to 2001, researchers tested memory in 16,000 of the nurses who reached age 70 and over during that period. No other study investigating the effects of eating berries on cognitive decline had been conducted on such a large scale.
Researchers found that nurses who ate the most blueberries (more than one half-cup serving a week) and strawberries (more than twice a week), were able to delay cognitive aging as much as 2.5 years. The study authors said other berries may have also contributed to the reduction in cognitive aging, but participants didn’t eat enough of them to collect viable data.
Anthocyanidins and the blood-brain barrier
Blueberries and Strawberries contain a specific flavonoid called anthocyanidin. Anthocyanidin give berries their dark, vivid colors. Other fruits such as raspberries, cherries, elderberries, and red and concord grapes are also rich in this particular flavonoid. The researchers noted that a unique quality of anthocyanidins is their ability to permeate the blood-brain barrier to affect the memory and learning centers of the brain.
Reducing dementia risk
The researchers emphasized that while their analysis found an association between eating berries and reduced cognitive decline, it did not prove a cause-and-effect relationship. There could be other factors linked to eating more berries, such as exercising more. Other studies have shown that resistance training along with maintaining a healthy weight can reduce dementia risk.
But little doubt remains that eating more fruit and vegetables is one of the best ways to stay healthy for a lifetime. And there probably isn’t any easier, more nutritious and delicious way of preserving your brain function than increasing your intake of blueberries and strawberries.