April 5, 2012 -- Can two or more servings of blueberries or strawberries a week help lower risk of Parkinson's disease?
Maybe, according to a new study published in Neurology.
Men and women who ate berries two or more times a week were nearly 25% less likely to develop Parkinson's disease than their counterparts who had less than one serving per month.
Exactly how these fruits may help lower risk is not known, but berries are rich in powerful antioxidants -- known as flavonoids -- which may protect brain cells from damage. Flavonoids are found in fruits and vegetables.
When the researchers looked at the data for men and women separately, the real benefit seemed to go to the men, not the women.
Overall, men who had the most flavonoids in their diet -- including sources such as berries, tea, apples, and red wine -- were 40% less likely to develop Parkinson's than those who ate the least.
Women who ate a high amount of flavonoids were no less likely to develop Parkinson's disease than those who ate the least amount, the study showed.
Parkinson's disease is a progressive neurologic disease that occurs when cells in the brain that make dopamine are slowly destroyed. Symptoms include tremors and difficulty with movement and walking.
The new study included more than 130,000 men and women. Of these, more than 800 developed Parkinson's disease during 20 years of follow-up.
"The main message from this study is that berry fruit is associated with lower risk of Parkinson's disease,"
says researcher Xiang Gao, MD, PhD. He is an assistant professor of medicine at Harvard Medical School in Boston.
Because the study found a link but did not show a cause-effect relationship, the findings need to be confirmed in other studies.
Still, there is no downside to eating berries, Gao tells WebMD. "It is not a bad idea to include berries in your diet, as they have other beneficial effects on other diseases."
He says future studies may look at whether eating more berries can slow the progression of Parkinson's disease.
More Study Needed on Berries and Parkinson?s Disease
Roy Alcalay, MD, is an assistant professor of neurology at Columbia University Medical Center in New York City. He says it is too soon to tell people to start snacking on berries to reduce their risk of developing Parkinson's disease. Alcalay is also an advisor for the Parkinson's Disease Foundation.
"It is interesting, but needs to be replicated," he says. "It is definitely worth more research."
Stuart Isaacson, MD, is excited about the new findings. He is the director of the Parkinson's Disease and Movement Disorders Center of Boca Raton and an associate professor of neurology at Florida International University's Herbert Wertheim College of Medicine in Miami.
"This is the first large study to show that people who eat berries and other sources of flavonoids have a lower risk of developing Parkinson's disease," he says.
In the past, nicotine and/or caffeine have been linked to lower risk for Parkinson's disease. "This is a more healthful and hopeful alternative."
There are lots of good reasons to eat berries, he says. "If you are looking for a healthy, holistic way of reducing your risk of Parkinson's disease because you think you are at higher risk, eating berries might make sense."
Whether it is something specific in the berries or a combined effect of the whole food remains to be seen. "It is always better to get your nutrients from a whole food as opposed to individual supplements," he says.
Roy Alcalay, MD, assistant professor of neurology, Columbia University Medical Center, New York City.
Xiang Gao, MD, PhD, assistant professor of medicine, Harvard Medical School, Boston.
Stuart Isaacson, MD, director of the Parkinson's Disease and Movement Disorders Center of Boca Raton, Fla.; associate professor of neurology, Florida International University's Herbert Wertheim College of Medicine, Miami, Fla.
Gao X. Neurology, 2012, study received ahead of print.