Milk and Parkinson's Disease: The Galactose Hypothesis

Several epidemiological studies have consistently reported an association between milk intake and a higher incidence of PD. Dairy foods were hypothesized to increase PD risk but the cause of this association was never determined. To date the main hypothesis fails to explain why consuming plain milk would expose to a higher risk of developing PD than consuming the same amount of other milk products. In this work the authors discuss the milk''s components that could participate in increasing the risk of developing PD and propose a new theory: galactose. Galactose is mainly found in milk. In human cells D-Gal induces aging through several mechanisms. It pushes cells into a hypermetabolic state forcing the cell to rely on aerobic metabolism. The authors describe the PD main mechanisms and compare them with the feature of galactose toxicity showing how in certain people high doses of this sugar could trigger a complex cascade of events and eventually increase the risk of developing this neurodegenerative disease.