WEDNESDAY, April 4 (HealthDay News) -- Regularly consumption of
food and drink rich in substances called flavonoids, such as
berries, apples, tea and red wine, can lower a man's risk of
developing Parkinson's disease by 40 percent, new research
suggests.
For women, however, a reduction in risk was only seen when they
ate at least several servings of berries a week, according to the
study. Men also had a risk reduction from frequently eating
berries.
"For total flavonoids, the beneficial result was only in men. But, berries are protective in both men and women," said the study's lead author, Dr. Xiang Gao, a research scientist at the Harvard School of Public Health and an associate epidemiologist at Harvard Medical School and Brigham and Women's Hospital in Boston.
"Berries could be a neuroprotective agent. People can include berries in their regular diet. There are no harmful effects from berry consumption, and they lower the risk of hypertension too," Gao added.
Results of the study are published online April 4 in the journal
Neurology.
Parkinson's disease is a degenerative condition that affects the
central nervous system. It causes movement disorders, such as
tremors, rigidity and balance problems. About 500,000 Americans
have Parkinson's disease, according to the National Institute of
Neurological Disorders and Stroke.
Flavonoids are substances found in plant foods that help prevent
damage to the body's cells, known as oxidative damage. Anthocyanins
are a type of flavonoid plentiful in such berries as strawberries
and blueberries.
For the study, the researchers reviewed nutrition and health
data from almost 50,000 men enrolled in the Health Professional
Follow-Up Study and more than 80,000 women participating in the
Nurses' Health Study.
The researchers looked at dietary intake of five major flavonoid
sources: tea, berries, apples, orange juice and red wine.
Over 20 to 22 years of follow-up, 805 people developed
Parkinson's disease -- 438 men and 367 women.
When researchers compared those who ate the most flavonoids with
those who ate the least, they found that only men saw a
statistically significant benefit, lowering their risk of
Parkinson's by 40 percent.
Gao said it wasn't clear why only men benefited from the extra
flavonoid intake, but he noted that other studies have also found
differences between men and women. Gao said it's not clear if
there's a biological mechanism causing these differences, or
another factor.
But, when the researchers looked at the dietary compounds
individually, it was clear that berries could benefit both men and
women, lowering the risk of Parkinson's disease by about 25 percent
for those who had at least two servings of berries a week.
Gao said that anthocyanins protect the cells from oxidative
damage and they also have an anti-inflammatory effect, which may be
how berries help to reduce Parkinson's risk.
The study findings should be interpreted cautiously because the
participants were mostly white professionals, and the results might
not apply to other ethnic groups. Also, recollections of dietary
intake may be faulty, and it's possible that other properties of
fruits and vegetables might have influenced the results, the
authors said.
Dr. Michael Okun, medical director of the National Parkinson
Foundation, said, "It is exciting to see research emerging about
modifiable dietary issues that may affect the risk of getting
diseases such as Parkinson's."
But, he added, it's important for people to realize that this
research isn't applicable to people who already have the
disease.
He also said it will be important to confirm these findings in
other studies and learn the mechanism of how berries and other
flavonoids appear to offer some protection against Parkinson's
disease.
More information
Learn more about Parkinson's disease from the
National Institute of Neurological Disorders and
Stroke.