Fibrates and statins activate the Peroxisome Proliferator-Activated Receptor alpha (PPAR-alpha). This nuclear receptor regulates genes governing inflammation, apoptosis and oxidative stress, three important mechanisms of neuronal death in Parkinson's disease (PD). We retrospectively studied the effect of statins and fibrates in a cohort of 419 patients with PD. In PD patients receiving either a statin or a fibrate, the mean age of disease onset was delayed by nearly 9 years, when compared with (control) PD patients not taking a lipid-lowering treatment. According to a mixed linear model, the increase in the levodopa-equivalent daily dose over 2 years was significantly smaller in the group taking a statin (+24 mg) than in the matched control group (+212 mg) (p=0.004), whereas the Unified Parkinson's Disease Rating Scale motor score progression was similar. The course of the disease in patients taking a fibrate did not differ from the controls. These data suggest that lipid-lowering drugs may have a disease modifier effect, with a stronger action for statins than for fibrates.