Dietary intake of antioxidant vitamins and risk of Parkinson's disease: a case-control study in Japan

Background: Antioxidant vitamins are expected to protect cells from oxidative damage by neutralizing the effects of reactive oxygen species. However, epidemiological evidence regarding the associations between antioxidant vitamin intake and Parkinson's disease (PD) is limited and inconsistent. We investigated the relationship between dietary intake of selected antioxidant vitamins, vegetables and fruit and the risk of PD in Japan using data from a multicenter hospital-based case-control study. Methods: Included were 249 patients within 6 years of onset of PD. Controls were 368 inpatients and outpatients without a neurodegenerative disease. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for sex, age, region of residence, pack-years of smoking, years of education, body mass index, dietary intake of cholesterol, alcohol, total dairy products, and coffee and the dietary glycemic index. Results: Higher consumption of vitamin E and beta-carotene was significantly associated with a reduced risk of PD after adjustment for confounders under study: the adjusted odds ratio in the highest quartile was 0.45 (95% confidence interval [CI]: 0.25-0.79, P for trend = 0.009) for vitamin E and 0.56 (95% CI: 0.33-0.97, P for trend = 0.03) for beta-carotene. Stratified by sex, such inverse associations were significant only in women. No material relationships were shown between intake of vitamin C, alpha-carotene, cryptoxanthin, green and yellow vegetables, other vegetables, or fruit and the risk of PD. Conclusions: Higher intake of vitamin E and beta-carotene may be associated with a decreased risk of PD.