From the October 2000 Issue of Nutrition Science News
Currently, 3 percent of the population older than 65 has Parkinson's disease, a neurological condition causing tremors, difficulty in walking and, eventually, death. Low levels of the neurotransmitter dopamine are found in the brains of Parkinson's patients, so the disease is usually treated with L-Dopa, a synthetic dopamine replacement. Now, however, there is evidence that coffee, which keeps dopamine levels up, may help prevent Parkinson's disease in the first place.
Webster Ross, M.D., of the University of Hawaii School of Medicine, explored the connection between caffeine and Parkinson's disease using data from the prospective longitudinal Honolulu Heart Program. In this study, Ross followed 8,004 men of Japanese ancestry living in Honolulu from 1968 to 1996. At the beginning of the study, the average age was 53 years. Consumption of coffee and noncoffee caffeine sources were assessed at the beginning of the study and again in the early 1970s. During the 30 years of follow-up, 102 men developed Parkinson's disease at an average age of 74 years. Coffee drinkers were much less apt to develop the condition, and the more cups of coffee they drank a day, the lower their risk fell. Noncoffee drinkers' risk of Parkinson's disease was more than five times that of men drinking 28 ounces or more of coffee daily. This finding is independent of other dietary factors such as smoking, consumption of milk and sugar, alcohol, and nutrients in coffee besides caffeine. Noncoffee caffeine consumption also lowered Parkinson's disease risk.
Caffeine stimulates the central nervous system by interfering with adenosine receptors. These receptors are believed to inhibit dopamine neurotransmission, thereby decreasing motor activity. Thus, caffeine may directly maintain dopamine levels and normal neural function.
Association of Coffee and Caffeine Intake with the Risk of Parkinson Disease
Journal of the American Medical Association 2000 (May 24); 283 (20): 2674–2679