So, are there bad news for the dairy council? Probably not. Increasingly, risk factors for Parkinson’s are being defined. Cigarette smoking is associated with a 50% lower risk, and exposure to pesticides, such as rotenone and paraquat, doubles the risk. Higher concentrations of serum urate lower the risk.
A new study found that higher consumption of dairy products or milk alone was associated with a higher risk for Parkinson’s in the Honolulu-Asia Aging Study. Drinking more than 2 cups of milk per day in midlife was now found in another report to lead to 40% fewer brain cells in areas affected by Parkinson’s. This association was seen only among nonsmokers.
The initial milk study concluded that contamination with heptachlor was the culprit for the risk rather than milk consumption alone. Possibly, however, in that milk consumption lowers plasma urate, that may lead to a higher risk. It is too soon to hope that limiting milk consumption will lower the risk of Parkinson’s.
See Neurology, 2016, page 496-497.