Abstract
It has been suggested that dietary antioxidants reduce Parkinson's disease (PD) risk by neutralizing free radicals, thus preventing injury to neurons in the substantia nigra. This caseβcontrol study examined the possible role of longβterm dietary antioxidant intake in PD etiology. Cases (n = 57) were males 45β79 years old with at least two cardinal signs of PD and no evidence of other forms of parkinsonism or dementia. Ageβmatched friend controls (n = 50) were chosen from lists provided by the cases. Usual dietary intake 20 years ago, including vitamins E and C and carotenoids, was assessed by a 102βitem food frequency questionnaire. Odds ratios and 95% confidence intervals were calculated using conditional logistic regression. Antioxidant intake, adjusted for age, education, smoking, rural living, and total energy intake, was not associated with reduced PD risk. Trends toward greater PD risk were associated with higher intakes of vitamin C and carotenoids, especially xanthophylls, reflecting higher intakes by PD cases of fruit and certain vegetables. Intakes of sweet foods, including fruit, were associated with higher PD risk, suggesting that the observed trends may be due to a preference for sweet foods. This study does not provide support for a protective effect of longβterm dietary antioxidant intake on PD risk.