Regularly eating berries and other foods high in compounds called anthocyanins can ward off Parkinson's disease, a new study suggests.
Men and women in the study who consumed the most anthocyanins — found in berries and apples — over two decades were about 25 percent less likely to develop Parkinson's disease than those who consumed the least, said study researcher Dr. Xiang Gao, of the Harvard School of Public Health in Boston.
Anthocyanins are one type of flavonoids, which are powerful antioxidants , and are good for "alleviating oxidative stress and suppressing neuroinflammation in the brain," Gao told MyHealthNewsDaily.
Flavonoids are commonly found in fruits, including berries, the cocoa beans used to make chocolate and citrus. But in the study, only the ones found in berries seemed to affect Parkinson's risk in both men and women. Other flavonoids seemed to affect only men's risk, the study said.
The study was released Feb. 13 and will be presented at the American Academy of Neurology's 63rd Annual Meeting in April.
Flavonoids in men and women
Gao and his colleagues examined flavonoid consumption — including tea, berries, apples, red wine, oranges and orange juice — in 49,627 men participating in the Health Professional Follow-up Study, and 80,171 women participating in the Nurses' Health Study.
After about 20 years, 782 people developed Parkinson's disease, the study said.
When they examined the consumption of all flavonoid-rich foods, the researchers found that the 20 percent of men who consumed the most flavonoids were 35 percent less likely to develop Parkinson's disease than the 20 percent of men who consumed the least flavonoids.
However, no such relationship was found for women, the study said.
Gao said he is not sure why there appears to be a gender difference for Parkinson's risk and overall flavonoid consumption. "Clearly, more studies are needed to explore this," he said.
But when the researchers looked at flavonoids found only in berries and apples — which are the anthocyanins — both women and men who consumed the most were about 25 percent less likely to develop Parkinson's than those who consumed the least, the study said.
Why are flavonoids good for us?
Parkinson's disease is caused in part by inflammation and oxidative stress in the brain , said Cristobal Miranda, an assistant professor of pharmaceutical sciences at Oregon State University, who was not involved in the study. Flavonoids have anti-inflammatory and anti-oxidative effects, he said.
"Flavonoids have this binding property, where they can bind some metals that are involved in the formation of free radicals," Miranda told MyHealthNewsDaily. Free radicals can damage DNA and limit cells' oxygen supply, he said.
Flavonoids tend to be found in the bits of plants that most people throw away, such as the pit, peel and core, said David Dexter, a neuropharmacology expert at Imperial College London in England, who was not involved in the study.
For example, flavonoids in tangerines are at their highest concentration in the fruit's peel, Dexter said. It could be that berries provide extra protection against Parkinson's because people eat them whole — including their skin and seeds, he said.
There are about 5,000 flavonoids in nature, but not all of them can cross the protective blood brain barrier and move into the brain, Dexter said. That could explain why anthocyanins warded off Parkinson's in both men and women, but other types of flavonoids worked only in men, he said.
"There are quite a few flavonoids that can get into the brain, but I think we need to do large, extended clinical trials to find them," Dexter told MyHealthNewsDaily.
Past research has suggested that flavonoids could reduce Parkinson's disease risk. A 2007 study in the Journal of the American College of Nutrition showed that the neurons of mice with Parkinson's disease were protected when their diets were supplemented with flavonoids.
Pass it on: Berries, which are rich in antioxidant flavonoids, can decrease the risk of developing Parkinson's disease by about 25 percent.
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