Antioxidants in adipose tissue and risk of myocardial infarction: the EURAMIC study

Summary Laboratory and epidemiological studies suggest that the antioxidants, vitamin E and β-carotene, protect against coronary heart disease. In a European multicentre case-control study α-tocopherol and β-carotene concentrations were measured in adipose-tissue samples collected in 1991-92 from 683 people with acute myocardial infarction and 727 controls. Mean adipose-tissue β-carotene concentration was 0·35 μg/g in cases and 0·42 in controls, with age-adjusted and centre-adjusted mean difference 0·07 μg/g (95% confidence interval [Cl] 0 04-0·10). Mean α-tocopherol concentrations were 193 μg/g and 192 μg/g for cases and controls, respectively. The age-adjusted and centre-adjusted odds ratio for risk of myocardial infarction in the lowest quintile of β-carotene as compared with the highest was 2·62 (95% Cl 1·79-3·83). Additional control for body-mass index and smoking reduced the odds ratio to 1·78(95% Cl 1·17-2·71); other established risk factors did not substantially alter this ratio. The increased risk was mainly confined to current smokers: the multivariate odds ratio in the lowest β-carotene quintile in smokers was 2·39 (95% Cl 1·35-4 25), whereas it was 1·07 for people who had never smoked. A low α-tocopherol concentration was not associated with risk of myocardial infarction. Our results support the hypothesis that high β-carotene concentrations within the normal range reduce the risk of a first myocardial infarction. The findings for α-tocopherol are compatible with previous observations of reduced risk among vitamin E supplement users only. The consumption of β-carotene-rich foods such as carrots and green-leaf vegetables may reduce the risk of myocardial infarction.