I do think Curcumin and predominantly veg diet are contributing to low incidence of PD in India. But the difference between western countries and India may not be as the present data suggested. Lindy is also correct about the number of cases reported.. There is yet another problem: the stigma attached to any disorder that is related to brain, and PD is considered a "mental disease". Nobody with the right mind announces that they have a "mental problem"!! So even people or families who know the diagnosis will not openly admit to it. Many times family i.e, husband/father/son/brother knows but not the patient and sometimes no one except the doctor. yes, it is true I have seen such incidents.

girija