Positive Health Online

Abstract

ASCHERIO and WILLETT and colleagues, Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02115 USA. alberto.ascherio@channing.harvard.edu write that antioxidants increase the resistance of low-density lipoprotein to oxidation, and may thereby reduce risk for atherosclerosis . The authors conducted a prospective observational study to determine whether intake of vitamin E, vitamin C or carotenoids predict risk for total or ischaemic stroke .

Background

Methodology

Participants were 43,738 men, aged 40-75 years, with no cardiovascular disease or diabetes, from the Health Professionals Follow-up study. Repeated and validated dietary assessments were carried out using a self-administered 131-item food-frequency questionnaire, which included questions regarding dose and duration of vitamin supplement use. Follow-up was for 8 years.

Results

There were a total of 328 strokes, of which 210 were ischaemic, 70 haemorrhagic and 48 unclassified. The relative risk for ischaemic stroke in the top quintile of vitamin E intake (median, 411 IU/day), compared with the bottom quintile (5.4 IU/day) was 1.18. The relative risk for ischaemic stroke in the top quintile of vitamin C intake (1167 mg/d) compared with the bottom quintile (95 mg/d) was 1.03. Results for total stroke were similar The associations of vitamin intake with haemorrhagic stroke were also nonsignificant, but the confidence intervals were wide. Neither dose nor duration of vitamin E or vitamin C supplement use was related to risk for total or ischaemic stroke. The relative risk for ischaemic stroke was 1.16 in men using 250 IU vitamin E supplementation per day compared with men using no vitamin E supplements, and was 0.93 in men using 700 mg or more of vitamin C supplementation per day compared with men using no vitamin C supplements. There was a significant inverse relation seen between lutein intake and risk for ischaemic stroke, but this was not independent of other dietary factors.

Conclusion

Vitamin E and vitamin C supplements and specific carotenoids did not substantially reduce risk of stroke in this cohort of men; however, modest effects cannot be excluded.

References

Ascherio A et al. Relation of consumption of vitamin E, vitamin C, and carotenoids to risk for stroke among men in the United States. Annals of Internal Medicine 130(12): 963-70. Jun 15 1999.