Laboratory and epidemiological studies suggest that the anti-oxidants, vitamin E and Beta -carotene, protect against coronary heart disease. In a European multicentre case-control study alpha -tocopherol and Beta -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 Beta -carotene concentration was 0.35 mu g/g in cases and 0.42 in controls, with age-adjusted and centre-adjusted mean difference 0.07 mu g/g (95% confidence interval [CI] 0.04-0.10). Mean alpha -tocopherol concentrations were 193 mu g/g and 192 mu g/g for cases and controls, respectively. The age-adjusted and centre-adjusted odds ratio for risk of myocardial infarction in the lowest quintile of Beta -carotene as compared with the highest was 2.62 (95% CI 1.79-3.83). Additional control for body-mass index and smoking reduced the odds ratio to 1.78 (95% CI 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 Beta -carotene quintile in smokers was 2.39 (95% CI 1.35-4.25), whereas it was 1.07 for people who had never smoked. A low alpha -tocopherol concentration was not associated with risk of myocardial infarction.
Our results support the hypothesis that high Beta -carotene concentrations within the normal range reduce the risk of a first myocardial infarction. The findings for alpha -tocopherol are compatible with previous observations of reduced risk among vitamin E supplement users only. The consumption of Beta -carotene-rich foods such as carrots and green-leaf vegetables may reduce the risk of myocardial infarction.