JohnT makes valid points about curcumin and possible negative effects. And that we can't be sure of it's benefits, or not, until clinical trials are made. This is all true but who can wait years for the results on a "drug" that drug companies can't make money on?
I remember reading somewhere that in India, tumeric - curcumin is widely used by the population. And that their PD rate is 1/10 that of western countries.