Combination of B Vitamins Slows Progression of Heart Disease

Several B vitamins are known to lower blood levels of homocysteine, a risk factor for coronary artery disease and stroke. But recent studies have yielded conflicting findings on the benefits of B vitamins in heart disease.

The latest study along these lines shows a clear benefit from the B vitamins -- but only in people who had elevated homocysteine levels at the beginning of the study.

Howard N. Hodis, MD, of the University of Southern California, Los Angeles, and his colleagues asked 506 men and women to take high doses of B vitamins or placebos daily for a little over three years. Specifically, they took 5 mg (5,000 mcg) of folic acid, 400 mcg of vitamin B12, and 50 mg of vitamin B6.

Hodis and his colleagues measured the subjects' carotid artery intima media thickness, an accepted way of measuring the progression of heart disease. As the intima media thickness increases, the artery's internal diameter decreases and less blood can flow through.

People with an initial homocysteine level of 9.1 mmol/L had a significantly lower rate of intima media thickening by the end of the study.

The researchers wrote that their findings were consistent with other research showing that the risk of cardiovascular disease increases significantly when homocysteine levels rise above 8 to 9 mmol/L.

Reference: Hodis HN, Mack WJ, Dustin L, et al. "High-dose B vitamin supplementation and progression of subclinical atherosclerosis." Stroke, Dec 31, 2008;epub ahead of print: doi 10.1161/stroke.aha.108.526798.