Vitamins No Benefit to Heart Disease? Study Results, and a Rebuttal from CRN
Vitamins No Benefit to Heart Disease _ Study
CHICAGO (Reuters) _ Post_menopausal women suffering from heart disease get no benefit from taking vitamin supplements and may be increasing their risk of developing artery blockages, researchers said on Tuesday.
In the 4_1/2_year study of 423 women, those who took supplements containing the anti_oxidant vitamins E and C to help fend off post_menopausal symptoms ended up with greater artery constriction than those taking inert placebos.
The same tendency toward artery constriction was found among study participants receiving hormone replacement therapy (HRT), and among those who took both HRT and vitamin supplements. HRT is designed to alleviate post_menopausal ailments from osteoporosis to hot flashes and vaginal dryness.
A much_publicized study in July showed long_term use of the most popular form of HRT, which is made using horse urine, raises the risk of heart disease as well as cancer and stroke. Hormone therapy was previously thought to have protective properties against coronary disease.
"The results of this trial add to the accumulating evidence that neither HRT nor antioxidant vitamin supplements improve the clinical course of coronary disease in post_menopausal women," Dr. David Waters, of San Francisco General Hospital, wrote in this week's Journal of the American Medical Association.
The vitamin dosage in the study was 400 units of Vitamin E and 500 milligrams of Vitamin C. Both vitamins are considered to have anti_oxidant properties that can boost the immune system and offset free radicals associated with the development of various diseases, including cancer.
Twenty_six of the patients taking the vitamin supplements either died, suffered a nonfatal heart attack or stroke, the same number as those taking HRT and outnumbering those taking placebos.
Waters called the finding about mortality related to vitamin intake "unexpected." Though it could be a "chance finding," he discouraged women from using both HRT and high doses of vitamins E and C.
A Rebuttal to the above:
Council for Responsible Nutrition questions WAVE study conclusions
Reminds consumers of scientific basis for safety and benefits of vitamins E and C
WASHINGTON, D.C., November 19, 2002 – The Council for Responsible Nutrition (CRN), one of the dietary supplement industry's leading trade associations, today responded to the conclusions drawn by the authors of the Women's Angiographic Vitamin and Estrogen (WAVE) Trial study as being "an exaggerated recommendation based on inconclusive data."
CRN noted that careful analysis of the study reveals the study showed no effects beyond random variations in response and that the researchers based their conclusions on statistically insignificant data.
"In fact, the actual data showed no difference in artery blockage between the antioxidant group and the control group, even after the researchers arbitrarily created 'worst_case' numerical values to fill missing data points," stated John Hathcock, Ph.D., vice president, nutritional and regulatory science, CRN. "Even those statistics that would appear to be significant are, in actuality, the exact pattern that would randomly occur if no treatments had been administered, and as the authors have stated, this could be a 'chance finding.'"
Further scrutiny exposes flaws in the study's design. For example, the study groups were not stratified to assure that all the treatment groups were similar with respect to the degree of coronary artery blockage. In addition, the authors concede that their study was powered only to detect the degree of blockage of the arteries, not the differences in clinical outcomes. Yet much of their discussion focuse