Intake of antioxidant vitamins and risk of Parkinson's disease

ABSTRACT Introduction Oxidative stress is proposed to be one of the potential mechanisms leading to neurodegeneration in Parkinson's disease. However, previous epidemiologic studies investigating associations between antioxidant vitamins, such as vitamins E and C and carotenoids, and PD risk have produced inconsistent results. Objective The objective of this work was to prospectively examine associations between intakes of antioxidant vitamins, including vitamins E and C and carotenoids, and PD risk. Methods Cases were identified in two large cohorts: the Nurses' Health Study and the Health Professionals Follow‐up Study. Cohort members completed semiquantitative food frequency questionnaires every 4 years. Results A total of 1036 PD cases were identified. Dietary intakes of vitamin E and carotenoids were not associated with PD risk; the multivariable‐adjusted relative risk comparing extreme intake quintiles were 0.93 (95% confidence interval: 0.75–1.14) and 0.97 (95% confidence interval: 0.69–1.37), respectively. Dietary vitamin C intake was significantly associated with reduced PD risk (relative risk: 0.81; 95% confidence interval: 0.65–1.01; p trend , 0.01); however, this result was not significant in a 4‐year lag analysis. For vitamins E and C, intake from foods and supplements combined were also unrelated to PD risk. Conclusions Our results do not support the hypothesis that intake of antioxidant vitamins reduces the risk of PD. © 2016 International Parkinson and Movement Disorder Society