APRIL 01, 2007

Calcium + Vitamin D = Improved Cholesterol Levels

Canadian researchers have found that a combination of calcium and vitamin D during weight loss in overweight and obese women could help improve their cholesterol levels. Calcium, either from dairy foods or supplements, has been linked with weight loss in various populations. A study published in 2006 stated that calcium supplements could help women lose weight. The recent study showed that calcium plus vitamin D also aids in lowering cholesterol levels. The results of the study were published in the January 2007 issue of the American Journal of Clinical Nutrition.

Researchers at Laval University, Ste-Foy, Canada, studied 63 women who were of healthy weight, overweight, or obese and assigned them to either a daily supplement of calcium plus vitamin D (600 mg/200 international units) or a placebo for 15 weeks. Both groups took part in a weight-loss program that restricted them to 700 kcal per day. At the end of the study, those who had taken the supplement showed significant improvements in both high-density lipoprotein cholesterol and low-density lipoprotein cholesterol, independent of changes in fat mass and waist circumference. Researchers said that a number of mechanisms may be responsible for the apparent effects of the supplements, including the role of calcium to interfere with fat absorption in the gut, boosting the body's ability to burn fat, or potentially having a satiety role.

Researchers Discover Arterial Plaque Rupture Process

Scientists at Columbia University Medical Center (New York, NY) have identified an important molecular process that can cause plaque rupture in patients with atherosclerosis. The findings could help scientists develop therapies that would prevent plaque ruptures, which can cause clots that can block blood flow and cause heart attacks and strokes. The findings were published in the December 26, 2006, issue of the journal Proceedings of the National Academy of Sciences.

The study found that macrophages—white blood cells that accumulate in the cholesterol-laden plaques along artery walls—die when 2 receptors on the cell's surface are activated at the same time. When these dead macrophages pile up, they become a significant trigger to plaque rupture. This finding comes with the promise of finding alternative methods of preventing plaque rupture outside of solely increasing levels of high-density lipoproteins with medication. "It's particularly important for us to consider alternative strategies and to understand the process behind the rupture of plaques," said researchers.

Niacin Effective at Raising HDL

Studies have shown that niacin, in its therapeutic form of nicotinic acid, can increase high-density lipoprotein levels by as much as 35%, as well as reducing levels of triglycerides by as much as 50%, when taken in high doses, usually about 2000 mg/day.

The Coronary Drug Project, a landmark study of 8341 men, aged 30 to 64 years, who had experienced heart attacks, found that niacin was the only treatment out of 5 that were tested that prevented second heart attacks. Men who took niacin had a 26% reduction in heart attacks and a 27% reduction in strokes, compared with men on placebos. Fifteen years later, the mortality rate among the men who took niacin was 11% lower than in those who took placebos. The researchers suggested that adding niacin to low-density lipoprotein-lowering statins can slow the progress of cardiovascular disease and reduce the risk of heart attack and other adverse outcomes by up to 35%.

Ideal Cholesterol Levels Challenged

A review paper published in the October 3, 2006, issue of the Annals of Internal Medicine has raised questions about the aggressive cholesterol-lowering recommendations made 2 years ago by the National Cholesterol Education Program. The panel urged patients at risk for heart disease to sharply reduce their low-density lipoprotein (LDL) levels and to attempt to reach very low levels. The authors of the paper argued that there is not enough solid evidence to support the target numbers set forth by the panel.

Until 2004, an LDL level of <130 mg/dL was considered to be sufficiently low. The updated guidelines, however, recommended that high-risk patients reduce their LDL levels to <100 mg/dL, while patients at very high risk were encouraged to lower their levels to <70 mg/dL. The authors examined all the studies that assessed the relationship between LDL and cardiovascular outcomes in patients with LDL <130 mg/dL and were unable to identify studies that provided evidence that reaching a certain LDL target level was important by itself, apart from other factors.