Tuesday, May 20, 2008 Dumaguing: Vitamins don't slow CVD dev't in high risk women By Dr. Victor Dumaguing To Your Health
ANTIOXIDANT vitamins and folic acid didn't slow the development of cardiovascular disease among high-risk women in two long-running, randomized trials, researchers reported at the American Heart Association's Scientific Sessions.
Results of the Women's Antioxidant and Folic Acid Cardiovascular Study (Wafacs) were presented last Monday in a late-breaking clinical trials session.
"Our study does not suggest that tasking folic acid, B6 or B12 primarily to prevent cardiovascular disease (CVD) would be worthwhile. Women who are taking them solely for that purpose may want to discontinue," said Christine M. Albert, M.D., M.P.H., lead author of the study and director of the Center for Arrhythmia Prevention at Brigham and Women's Hospital in Boston, Mass.
Researchers found no adverse effects from the vitamins but said there are other important non-cardiac reasons to take them including during pregnancy, when a woman's nutritional needs are higher. Folic acid supplementation has been associated with reducing birth defects of the brain and spinal cord.
WAFACS is a randomized, placebo-controlled study of folic acid and other B vitamins in a subset of 5,442 women participating in a larger trial called Women's Antioxidant Cardiovascular Study (Wacs). WACS is a randomized, placebo-controlled trial of antioxidant vitamins with 8,171 females. Participants were health professionals over age 40 who either had a history of CVD or were considered at high risk due to three or more CVD risk factors such as high blood pressure, high cholesterol levels, diabetes and smoking.
Researchers compared the effects of a combination of folic acid (2.5 milligrams daily), vitamins B6 (50 mg daily) and vitamin B12 (1 mg daily) versus placebo in reducing risk of major vascular events including coronary heart disease, heart attack and stroke. Researchers tracked the women for 7.3 years and checked for heart attacks, strokes, coronary revascularization procedures and cardiovascular-related deaths.
They found that women taking the vitamins/folic acid combination were just as likely to suffer a major vascular event.
Researchers also investigated whether decreasing homocysteine levels from folic acid supplementation would be associated with reductions in CVD events. Homocysteine levels increase with advancing age, kidney disease and other well-documented cardiovascular risk factors.
Some studies have associated elevated blood levels of homocysteine, a by-product of protein metabolism, with increased risk of CVD. But it is unknown whether homocysteine is a risk factor or a marker of pre-existing cardiovascular disease. This study seems to support that it is a marker, Albert said.
In the antioxidant vitamin trial, Wacs, researchers found no cardiovascular benefits from three antioxidants -- Vitamin C, Vitamin E or beta-carotene -- on the primary end point of CVD during 9.4 years of follow-up, said JoAnn Manson, M.D., Dr. P. H., chief of the Division of Preventive Medicine at Brigham and Women's Hospital in Boston, Mass., and the Elizabeth F. Brigham Professor of Women's Health at Harvard Medical School.
While earlier randomized trials had failed to find evidence that antioxidants were beneficial for CVD, WACS was the first to examine the effect of Vitamin C alone on the risk of CVD.
In pre-specific subgroup analyses of Was, women who were randomized to the vitamin C group and who smoked or who had three or more risk factors but did not have prevalent CVD seemed at reduced risk of stroke. Those with prior CVD who took Vitamin E also had a significant reduction in cardiovascular events.
Although those findings may have been due to chance, they warrant further investigation, the researchers said.
