Atherosclerosis, or the formation of plaques and lesions in the coronary arteries, may signal the development of cardiovascular disease (CVD) early in life, perhaps decades before any explicit clinical diagnosis of CVD is made. Adequate intakes of antioxidant vitamins are known to protect against plaque formation, and yet most research into the effects of these vitamins has focused on subjects who already had overt signs of heart disease such as myocardial infarction, angina, stroke, or heart attack. Healthy middle-aged women without overt CVD were the focus of a new study by Iannuzzi et al. published this month in the American Journal of Clinical Nutrition. In examining the relationship between the women's antioxidant vitamin consumption and the presence of plaques in the common carotid arteries, the authors concluded that low vitamin E intake is a risk factor for early atherosclerosis.
The 307 southern Italian women subjects of the study averaged 56 years of age, had no clinical history of CVD, and did not take vitamin supplements containing the antioxidants vitamins A, C, or E. Their average daily intakes and plasma concentrations of antioxidants were determined through food frequency questionnaires and blood samples. In addition, ultrasound examinations of the carotid arteries and bifurcations (branches) were performed. Among the group, 66% had atherosclerotic plaques at one or more sites in the carotid arteries and 34% had no plaques.2 Low intakes of vitamin E were significantly associated with plaques in the carotid bifurcations, which are the sites where most early atherosclerosis begins. Women with the lowest intakes and plasma concentrations of vitamin E were more than twice as likely to have this type of plaque.4 Intakes and concentrations of vitamins A and C were not associated with carotid plaques.
The Southern Italian women in the study recorded their dietary vitamin E sources chiefly from legumes, vegetables, and olive oil. Only people with very low intakes and plasma concentrations of vitamin E could be expected to benefit from an increase of vitamin E; therefore, the authors caution that before altering one's diet or taking antioxidant supplements, it would be helpful to assess daily vitamin E intakes with the help of a physician.