The present study examined the effects of anti-oxidant vitamin supplementation on mood and cognitive functioning in 205 volunteers (110 females, 95 males; age range: 60-80 years). In this randomised, double-blind, placebo-controlled study, the volunteers received either anti-oxidant supplementation (daily dosage 12mg/d β-carotene, 400 mg/d α-tocopherol and 500mg/d ascorbic acid) or placebo. The volunteers were followed up for 12 months. Vitamin levels were assessed from plasma samples. The primary outcome measures were subjective mood, self-reported cognitive failures, and measures of intelligence. These were measured at 4, 8 and 12 months. There were very few significant differences between the placebo and vitamin groups. Analysis of the effects of changes in vitamin levels on mood and cognition revealed significant effects of changes in vitamin C but not the other anti-oxidants. Increases in vitamin C were associated at 12 months with more positive mood, greater improvements in global assessments of intellectual functioning and a reduction in everyday errors of memory, attention and action. These effects were greatest for those volunteers who had a more negative mood and lower levels of cognitive function at baseline. Overall, results support earlier findings based on examination of dietary intake.
Keywords: Anti-oxidant vitamins; Cognition; Elderly; Mood; Vitamin C.