We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.
Survival in Parkinson disease: thirteen-year follow-up of the DATATOP cohort.
To investigate predictors of survival in Parkinson disease (PD).
                Vital status was determined in 800 subjects enrolled in a clinical trial of deprenyl (selegiline) and tocopherol 13 years earlier.
                Two hundred ninety-six deaths were recorded. There was no difference in the standardized mortality ratios across gender or age group. In univariate analyses, PD-specific variables associated with mortality were increased symmetry of parkinsonism, gait dysfunction as an initial symptom, severity of parkinsonism, and rate of worsening of parkinsonism prior to study enrollment. Cumulative exposure to deprenyl was not associated with mortality. In multivariable analysis, severity of parkinsonism and rate of worsening of parkinsonism remained associated with mortality. A poorer response to levodopa was associated with increased mortality independent of disease severity or dosage of levodopa. Results were unchanged when the analysis was restricted to 747 subjects maintaining a most likely diagnosis of PD throughout 6 years of active follow-up.
                Parkinson disease did not affect survival differently across gender or age groups in this selected group of otherwise healthy clinical trial participants. Severity and rate of worsening of parkinsonism and response to levodopa are strongly related to survival.