HONOLULU, HAWAII. About three per cent of all Americans over the age of 65 years now suffer from Parkinson's disease (PD). Although a small proportion of cases can be traced to a genetic defect most are believed to be environmental in origin. Researchers at the Department of Veterans Affairs have just released a major report that concludes that smoking and drinking coffee provide significant protection against developing PD. Their study involved 8000 Japanese-American men who were enrolled in the Honolulu Heart Program between 1965 and 1968. The men's smoking status and intake of coffee, caffeine, and other dietary components were determined at enrollment and six years later. After 30 years of follow-up 102 of the men had been diagnosed with PD. The median age for initial diagnosis was 73.6 years (range was 54-89 years). Nondrinkers of coffee were found to have a five times greater risk of developing PD than did men who drank seven cups (4 oz servings) or more of coffee a day. Overall, nondrinkers had a two to three times greater risk of PD than coffee drinkers even after adjusting for smoking and other variables. Smoking was also found to be protective with nonsmokers having a 3.5 times greater risk of PD than current smokers. Smokers who also consumed moderate amounts of coffee (3- 4 4 oz cups/day) had a risk of developing PD that was five times less than that of a nonsmoking, non-coffee-drinking man. Other forms of dietary caffeine sources were also found to be protective. The researchers speculate that caffeine exerts its protective effect through its stimulation of the central nervous system.
Ross, G. Webster, et al. Association of coffee and caffeine intake with the risk of Parkinson disease. Journal of the American Medical Association, Vol. 283, May 24/31, 2000, pp. 2674-79