L A Yochum1, A R Folsom, L H Kushi. 1. Intergroup of Arizona, Phoenix, and the Division of Epidemiology, the University of Minnesota, Minneapolis 55454, USA.
Abstract
BACKGROUND: Antioxidant vitamins may play a role in the prevention of stroke because they scavenge free radicals and prevent LDL oxidation. Epidemiologic studies that have examined this relation produced conflicting results. OBJECTIVE: We examined the association between antioxidant vitamin intakes and death from stroke. DESIGN: This was a prospective cohort study of 34492 postmenopausal women. RESULTS: During follow-up, 215 deaths from stroke were documented. Total vitamin A, carotenoid, and vitamin E intakes were not associated with death from stroke after multivariate adjustment. Relative risks (RRs) and 95% CIs of the highest compared with the lowest category were 0.79 (0.45, 1.38; P for trend = 0.33) for vitamin A, 0.80 (0.45, 1.40; P for trend = 0.40) for carotenoids, and 0.91 (0.55, 1.52; P for trend = 0.86) for vitamin E. The test for trend for total vitamin C intake was significant, although the association appeared somewhat U-shaped, not monotonic. An inverse association was seen between death from stroke and vitamin E intake from food. RRs (and 95% CIs) of death from stroke from the lowest to highest intake categories were 1.0, 0.80 (0.51, 1.26), 0.93 (0.58, 1. 49), 0.67 (0.39, 1.14), 0.40 (0.20, 0.80); P for trend = 0.008. The results suggest inverse associations between death from stroke and intakes of the most concentrated vitamin E food sources consumed by this cohort: mayonnaise, nuts, and margarine. CONCLUSIONS: Our results suggest a protective effect of vitamin E from foods on death from stroke but do not support a protective role for supplemental vitamin E or other antioxidant vitamins. However, given the number of deaths from stroke in the present cohort, a small-to-moderate association could not be ruled out.
BACKGROUND: Antioxidant vitamins may play a role in the prevention of stroke because they scavenge free radicals and prevent LDL oxidation. Epidemiologic studies that have examined this relation produced conflicting results. OBJECTIVE: We examined the association between antioxidant vitamin intakes and death from stroke. DESIGN: This was a prospective cohort study of 34492 postmenopausal women. RESULTS: During follow-up, 215 deaths from stroke were documented. Total vitamin A, carotenoid, and vitamin E intakes were not associated with death from stroke after multivariate adjustment. Relative risks (RRs) and 95% CIs of the highest compared with the lowest category were 0.79 (0.45, 1.38; P for trend = 0.33) for vitamin A, 0.80 (0.45, 1.40; P for trend = 0.40) for carotenoids, and 0.91 (0.55, 1.52; P for trend = 0.86) for vitamin E. The test for trend for total vitamin C intake was significant, although the association appeared somewhat U-shaped, not monotonic. An inverse association was seen between death from stroke and vitamin E intake from food. RRs (and 95% CIs) of death from stroke from the lowest to highest intake categories were 1.0, 0.80 (0.51, 1.26), 0.93 (0.58, 1. 49), 0.67 (0.39, 1.14), 0.40 (0.20, 0.80); P for trend = 0.008. The results suggest inverse associations between death from stroke and intakes of the most concentrated vitamin E food sources consumed by this cohort: mayonnaise, nuts, and margarine. CONCLUSIONS: Our results suggest a protective effect of vitamin E from foods on death from stroke but do not support a protective role for supplemental vitamin E or other antioxidant vitamins. However, given the number of deaths from stroke in the present cohort, a small-to-moderate association could not be ruled out.