Hormone Replacement Therapy, Antioxidants May Worsen Heart Disease
Postmenopausal women with obstruction in their coronary arteries who take hormone replacement therapy (HRT) or antioxidant supplements may worsen their heart disease, according to a new study in the Journal of the American Medical Association (2002;288:2432–40). While the findings of this study add to the body of evidence that HRT increases heart disease risk, this is the first study to suggest that taking antioxidants may also cause harm to the heart.
In this study, 423 postmenopausal women older than 55 years with at least one obstructed coronary artery were assigned to receive HRT or placebo, with or without 800 IU of vitamin E and 1,000 mg of vitamin C per day, for approximately 3 years. Pictures taken of heart vessels (angiograms) were performed initially and at the conclusion of the study to measure changes in the diameter of the blood vessel opening.
The average coronary artery diameter worsened (i.e., the arteries became narrower and more obstructed) in each of the treatment groups, compared with initial measurements. The greatest change was seen in women taking HRT plus antioxidants, while the smallest change was in those taking placebo. A surprising finding was that women who took vitamins E and C had a worse outcome than women who did not receive the vitamins. The authors had no explanation for this finding.
Although these negative results with antioxidant supplements are consistent with the findings from a few other studies, some research has demonstrated a clear benefit from antioxidant supplementation. For example, in a 1996 study published in Lancet, supplementation with vitamin E by heart patients (400 or 800 IU per day) for approximately 18 months reduced the incidence of heart attacks by 77%. Several other studies have shown that vitamin E increases pain-free walking distance in people with atherosclerosis of the lower extremities.
The conflicting results seen in various antioxidant studies may be due to differences in nutritional status among the different study populations. There is good evidence that a wide range of nutrients other than vitamins E and C are important for maintaining a healthy heart and blood vessels. Magnesium, vitamin B6, folic acid, selenium, copper, zinc, and chromium have all been shown in either human or animal studies, or both, to be beneficial for the prevention or treatment of cardiovascular disease. Nutrients work in the body as a team, and all of them must be present in adequate amounts in order to promote good health. If magnesium, for example, were the weakest link in the nutritional chain, one would not expect antioxidants to do much good until the magnesium deficiency was corrected. Taking large amounts of just two vitamins might even be harmful, if doing so caused an imbalance with other nutrients. Rather than testing only one or two nutrients at a time, researchers should use a supplement that contains all of the nutrients known to promote heart health.
Several studies have been published showing that HRT contributes to the development of heart disease. The Heart Estrogen/Progestin Replacement Study (HERS) found that HRT led to a higher risk of stroke and heart attack during the first year of HRT therapy. The Women’s Estrogen for Stroke Trial (WEST) showed an increased stroke risk after six months of starting HRT. The most recent study, the Women’s Health Initiative, was stopped prematurely after five years due to increases in the incidence of heart disease and breast cancer in women taking HRT.
Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of The Natural Pharmacist: Lowering Cholesterol (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice at New England Family Health Associates located in Southport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.
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