Caffeine Reduces Risk of Parkinson’s Disease

Abstract

Parkinson’s disease (PD) is a chronic degenerative brain disease and there is no preventive measure against it. Treatment is only symptomatic to relieve movement disorders associated with the disease. Currently available drugs are effective for short period of time lasting only few years and cannot relieve non-movement disorders. Currently, there are several epidemiological studies both case-control and prospective, reported that coffee drinking can reduce risk of PD and this reduced risk is mostly related to the amount of coffee consumption. Coffee prevention of PD seems to be more remarkable in male than in female. However, in females who did not use hormone replacement therapy or in very old age, coffee consumption can reduce the risk equally in both sexes. Tea has recently also been found to reduce the risk of PD. Since both coffee and tea contain caffeine, therefore it is reasonable to imply its role in the prevention of PD albeit prevention of the disease of tea consumption is weaker than coffee consumption. The plausible explanation for this difference might be that the amount of caffeine per serving in tea is much less than in coffee. Experimentally induced PD in rats or mice by either 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine or 6-hydroxydopamine found that pretreatment with caffeine effectively prevents the development of PD. Caffeine is known to non-selectively block adenosine 1 and 2A receptors (A₁R and A_2AR) and that implication of caffeine’s effect to prevent PD is blocking of A_2AR. Thereafter, new compounds with more selective A_2AR blockade have been developed and currently are in Phase 2 and 3 clinical trials. Preliminary results indicate that these compounds can reduce several symptoms of PD but their long term efficacy and in larger number of patients are awaiting to validate their true efficacy.