An intriguing conclusion reported in the Journal of the American Medical Association for May 24/31 is that consuming coffee or caffeine in moderate quantities reduces the subsequent risk of developing Parkinson's disease. Observations carried out by neurologists in Honolulu have indicated that non-coffee drinkers are two to three times more liable to suffer from the disease late in life than are those who like their coffee. Indeed, those who consume seven or more cups of the beverage daily run only one fifth the risk of Parkinson's disease compared with non-drinkers.
Data were derived from 8,004 men of Japanese ancestry aged 45 to 68 years and living on the Hawaiian island of Oahu. After follow-up for six years, 102 of the group were diagnosed as suffering from the disease. This incidence appeared to be independent of the tobacco habit.
The constituent of coffee held responsible for protection was caffeine, although the mechanism of its effect remains obscure. The nicotinic acid or nicotinamide present was believed not to be involved.
Caffeine may exert its effect by helping to maintain dopamine levels by counteracting compounds which inhibit its transmission. Apparently the consumption of milk or sugar in coffee made no difference to its protective activity.