Berries may offer sweet hope in reducing the risk of Parkinson’sdisease, Harvard researchers are reporting.
The Harvard School of Public Health examined the effect onParkinson’s disease of flavonoids, a dietary component found incitrus fruits, chocolate and berries. The study was released lastSunday, and will be presented at the American Academy ofNeurology’s 63rd Annual Meeting in Honolulu in April.
The exact reason people develop Parkinson’s is not clear, thoughsome genetic and environmental factors are thought to beresponsible.
“The study opens up a whole area of potential future studiesexamining other types of environmental effects on Parkinson’s,”said Dr. Anna Hohler, a neurologist and professor of neurology atBoston University who was not involved with the study.
The study found that the top 20 percent of males who consumedthe most flavonoids were 40 percent less likely to developParkinson’s than the bottom 20 percent of men who consumed theleast amount of flavonoids. In women, there was no correlationbetween overall flavonoid consumption and Parkinson’s.
However, a subclass of flavonoid called anthocyanins, which areprimarily found in berries, were associated with reduced risk ofdeveloping Parkinson’s, said study author Dr. Xiang Gao, researchscientist at Harvard.
“These components we found to have neuroprotective effects,” hesaid. “Anthocyanins are a kind of pigment in food. for example, ina blackberry or a strawberry, when you see the different colors inthese berries, that’s because of anthocyanin.”
The study examined 129,617 individuals – 49,281 men and 80,336women. Participants were followed for 20 to 22 years, and wereasked to periodically fill out questionnaires about their foodconsumption habits. During that period, 805 participants developedParkinson’s. when the study started, the average age of maleparticipants was about 55, and the average age of femaleparticipants was about 51, Gao said.
Parkinson’s is a neurodegenerative disorder that affectsmovement. Most people with the disease start to get symptoms intheir sixties, though some people get it much earlier, Hohlersaid.
An estimated 60,000 Americans are diagnosed with Parkinson’sdisease each year, and as many as one million Americans live withParkinson’s, according to the Parkinson’s Disease Foundation in NewYork.
The study did not track the consumption of all types of berries,but looked specifically at strawberries and blueberries.
“We asked about a number of different dietary items – howfrequently they were eaten and the intake per month of each item,”Gao said. “That means we could only list the most consumedfoods.”
Participant’s questionnaires were then stored in a databasewhere researchers could later revisit answers and calculateaverages.
A strength of the study is the fact that people’s eating habitswere tracked before any of them had Parkinson’s, Gao said.
“Otherwise, if you do a kind of study called a case-controlstudy, in which you start with a group of people who already haveParkinson’s disease and ask them to recall their dietary intakefive years later, there may be some error,” he said. “This way wereduce this kind of memory bias.”
Gao said the link between flavonoid consumption on Parkinson’sand gender could not be confirmed until further studies takeplace.
“Our study is the first prospective study in humans,” he said.”So our observations need to be confirmed by other studies to seeif there is a difference. and if the other studies find some sortof gender, the next step is to do some more studies to understandthe mechanism.”
The study raises further questions about the consumption ofanthocyanin as well.
“Future research needs to find out in terms of quantity, howmuch do you need to consume to have a beneficial effect and in whatperiod of time,” Hohler said.
Although Gao agreed that more research must be done before anystrong conclusions are made, he said there is certainly no harm ineating more berries.
“Although it’s too early to recommend eating berries to reduceParkinson’s risk, think about the other beneficial effects ofberries,” he said. “If you only eat one cup of berries a month,maybe you can increase to another one.”
Hohler plans to discuss the study with Parkinson’s patients.
“When a study comes out like this, we say, ‘There is one studyso far which is interesting and may suggest that this might besomewhat neuroprotective,’ but that further studies need to be doneto clarify,” she said. “Parkinson’s patients are very eager to trythings that might decrease their chance of developing [thedisease].”