Follow-up study of early-life protective and risk factors in Parkinson's disease.

Previous studies suggest that Parkinson's disease (PD) is negatively associated with early-life intake of vitamin E-rich foods and positively associated with rural experience. Using a new survey design, we attempted to confirm and extend these results. We gave a telephone questionnaire to 106 patients with PD and to their spouses as controls. It assessed premarital consumption of 31 foods of various vitamin E content, vitamin supplements, and exposure to rural living. Respondents rated food consumption with respect to what they perceived as the average for their sex and age at that time. We found female patients with PD less likely than spouses to have eaten "peanuts and peanut butter" (p less than .05), which are high in vitamin E. "Salad with dressing," also high in vitamin E, gave a similar result (p less than .05) for a male-predominant patient group. Separate comparison of male controls with female controls ruled out sex-related preferences as the explanation of our findings. Patients had more extensive rural experience and were more likely to have frequently sprayed pesticides (p less than .05) than had controls. Our results justify further investigations into early-life vitamin E intake, pesticides, and neurotoxins associated with rural life.