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Preliminary research has led to a widely held belief that vitamin E may help prevent or delay coronary heart disease [13]. Researchers have reported that oxidative changes to LDL-cholesterol (sometimes called "bad" cholesterol) promote blockages (atherosclerosis) in coronary arteries that may lead to heart attacks. Vitamin E may help prevent or delay coronary heart disease by limiting the oxidation of LDL-cholesterol [14]. Vitamin E also may help prevent the formation of blood clots, which could lead to a heart attack. Observational studies have associated lower rates of heart disease with higher vitamin E intake. A study of approximately 90,000 nurses suggested that the incidence of heart disease was 30% to 40% lower among nurses with the highest intake of vitamin E from diet and supplements. Researchers found that the apparent benefit was mainly associated with intake of vitamin E from dietary supplements. High vitamin E intake from food was not associated with significant cardiac risk reduction [15]. A 1994 review of 5,133 Finnish men and women aged 30-69 years also suggested that increased dietary intake of vitamin E was associated with decreased mortality (death) from heart disease [16].
Even though these observations are promising, randomized clinical trials raise questions about the efficacy of vitamin E supplements in the prevention of heart disease. The Heart Outcomes Prevention Evaluation (HOPE) Study followed almost 10,000 patients for 4.5 years who were at high risk for heart attack or stroke [17]. In this intervention study the subjects who received 265 mg (400 IU) of vitamin E daily did not experience significantly fewer cardiovascular events or hospitalizations for heart failure or chest pain when compared to those who received a placebo (sugar pill). The researchers suggested that it is unlikely that the vitamin E supplement provided any protection against cardiovascular disease in the HOPE study. This study is continuing, with the goal of determining whether a longer duration of intervention with vitamin E supplements will provide any protection against cardiovascular disease.
In a study sponsored by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, postmenopausal women with heart disease who took supplements providing 400 IU vitamin E and 500 mg vitamin C twice a day, either alone or in combination with hormones, did not have fewer heart attacks or deaths. There was also no change in progression of their coronary disease. This study, The Women's Angiographic Vitamin and Estrogen (WAVE) trial, studied 423 postmenopausal women at seven clinical centers in the U.S. and Canada. In postmenopausal women with coronary disease enrolled in this trial, neither hormone replacement therapy nor antioxidant vitamin supplements provided cardiovascular benefit [18].
Results of the Women's Health Study, the Women's Antioxidant and Cardiovascular Study and the SuVIMAX study, all of which are investigating the effects of vitamin supplements on the progression of coronary heart disease, are due in 2005 and will provide additional information on the association between vitamin E supplements and cardiovascular disease.
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