The research, which is due to be presented at the American Academy of Neurology's 63rd Annual Meeting in April, suggests that men and women who regularly consume foods that are rich in anthocyanins – like berries – have a lower risk of developing Parkinson's disease.
Moreover, a flavanoid rich diet –including apples and oranges – may cut the chances of developing the disease by up to 40 per cent in men.
“This is the first study in humans to examine the association between flavonoids and risk of developing Parkinson's disease,” said study’s lead author Dr Xiang Gao, from the Harvard School of Public Health, Boston.
“Our findings suggest that flavonoids, specifically anthocyanins, may protect against the development of Parkinson’s disease … These data support the growing experimental evidence for neuroprotective effects of these compounds,” wrote the researchers.
“Our findings suggest that flavonoids, specifically a group called anthocyanins, may have neuroprotective effects. If confirmed, flavonoids may be a natural and healthy way to reduce your risk of developing Parkinson's disease,” they added.
Parkinson's disease, named after Dr James Parkinson, the London doctor who initially identified it as a particular condition, is a degenerative condition affecting movement and balance in more than one million Americans each year – a figure expected to rise due to ageing populations.
The disease affects nerve cells in several parts of the brain and central nervous system, particularly those that use the chemical messenger dopamine to control movement – especially the substantia nigra region of the brain.
Flavonoids are secondary plant metabolites, found that are found in many fruits and berries. They are known for their properties as pigments and antioxidant properties, which have been suggested to have neuroprotective properties. A 2007 study by Tarozzi et al (Neuroscience Letters, doi: 10.1016/j.neulet.2007.07.017), suggested that anthocyanins “may play an important role in brain health promotion, due to their ability to increase cell antioxidant capacity.”
Dr Gao noted that previous experimental studies have suggested that flavonoids and flavonoid-rich foods may exert protective neuroprotective effects, which may reduce the risk of Parkinson’s disease However, they said that to date, an association has not been examined in prospective human studies.
The Harvard researchers conducted a prospective study of nearly 50,000 men and over 80,000 women from the Health Professional Follow-up Study and Nurses' Health Study respectively.
After more than 20 years of following volunteers, the researchers analysed the association between flavonoid intakes and the risk of developing Parkinson's disease by looking at the consumption of five major foods rich in flavonoids: tea, berries, apples, red wine and oranges or orange juice.
After adjusting for confounding factors, the researchers found that men in the highest 20 percent for flavonoids intake had a 35 per cent lower risk of developing Parkinson’s disease risk than those in the lowest 20 percent for consumption.
In women, there was no relationship between overall flavonoid consumption and the risk of developing Parkinson's disease. But when sub-classes of flavonoids were examined, regular consumption of anthocyanins wase found to be associated with a lower risk of Parkinson's disease in both men and women.
Further details of the study are to be presented in April at the American Academy of Neurology’s meeting in Honolulu.
Source: American Academy of Neurology
AAN 63rd Annual Meeting Abstract
“Habitual intake of dietary flavonoids and risk of Parkinson disease”
Authors: X. Gao, A. Cassidy, M.A. Schwarzschild, E.B. Rimm, A. Ascherio