In the first comprehensive examination of caffeine consumption from a variety of sources and the risk of developing Parkinson’s disease, researchers from the Harvard School of Public Health (SPH) have determined that moderate consumption of caffeine reduces the risk of Parkinson’s disease in men and women. The findings are published on the Web site for the Annals of Neurology at http://www.interscience.wiley.com/jpages/0364-5134/.
Parkinson’s disease is a progressive nervous disease occurring generally after age 50. It destroys brain cells that produce the chemical dopamine, lack of which leads to the muscular tremor, slowing of movement, weakness, and facial paralysis that characterize the disorder.
Men who drank four to five cups per day of caffeinated coffee cut the risk of developing Parkinson’s disease nearly in half compared with men in the study who consumed little or no caffeine daily. Women who consumed between one and three cups of caffeinated coffee per day also cut their risk of developing Parkinson’s disease nearly in half when compared with women who drank less than a cup of coffee per day, but this apparent benefit was lost at higher levels of intake. Further research with women is required.
To examine the relationship between coffee and caffeine consumption, participants were chosen from the Health Professionals Follow-up Study at SPH and the Nurses’ Health Study, a Brigham and Women’s Hospital-based study. More than 47,000 men and 88,000 women, who were free of Parkinson’s disease, cancer, or stroke, were chosen. Participants completed comprehensive lifestyle and dietary questionnaires at the start of the study and turned in updated versions every two to four years. During the course of the study, 288 cases of Parkinson’s disease were diagnosed among the study participants.
The questionnaires contained inquiries on more than 100 food items; among them were coffee with caffeine, tea (nonherbal), cola beverages, chocolate, decaffeinated beverages, and soft drinks with and without caffeine.
Alberto Ascherio, lead author and associate professor of nutrition and epidemiology at the School of Public Health, said, “Our findings are useful in understanding how to prevent or treat disease. It would be premature to conclude that individuals should increase their caffeine consumption to prevent Parkinson’s disease. There’s no need to stampede to Starbucks to drastically increase one’s intake of coffee; moderate caffeine consumption provides the protection.”
The SPH study findings are similar to the conclusions in a study by Michael A. Schwarzschild, assistant professor of neurology at the Medical School. Using a mouse model of Parkinson’s disease, his team found that caffeine is protective against the disease. Schwartzschild’s study will appear in the May 15 issue of the Journal of Neuroscience.
Alberto Ascherio’s research was funded by a grant from the National Institutes of Health.