Overweight and obese women who took calcium and vitamin D supplements while dieting had improved cholesterol levels, according to results from a new study.

Researchers from Laval University, Sainte Foy, Canada, recruited 63 overweight or obese but otherwise healthy women whose diets included less than 800 mg per day of calcium. The recommended daily allowance for calcium in the U.S. is 1,000 mg, and 800 mg for Europe. Scientists placed the women on a 15-week diet plan that allowed 700 fewer calories per day than the women normally consumed. Each woman took a placebo or a tablet that contained 600 mg of elemental calcium and 200 IU of vitamin D, twice per day.

Compared to placebo, at the end of the 15-week treatment period, those who had taken calcium and vitamin D had significantly improved high-density lipoprotein (HDL, the "good" cholesterol) compared to total cholesterol and to low-density lipoprotein (LDL, the "bad" cholesterol). Doctors noted that the beneficial changes in the relationship of HDL to total cholesterol, and HDL to LDL did not depend on changes in body fat (fat mass) or waist size. Those who took calcium and vitamin D also had higher absolute levels of HDL, lower absolute levels of LDL, lower levels of total cholesterol, and other blood fats (triacylglycerol, or triglycerides) compared to placebo.

The scientists believe that calcium may reduce the amount of fat that passes from the gut to the bloodstream, may improve the ability of the body to burn fat, and may help people feel full (satiety).

Reference: American Journal of Clinical Nutrition: January, 2007; Vol. 85, No. 1, 54-9.

Selenium yeast kept bad fats from forming in the blood after a fatty meal, according to results from a new study.

Doctors from the Free Radical Research Group, National Research Institute for Food and Nutrition, Rome, Italy, reported that eight healthy men and six healthy women, aged 25 to 40, ate a special high-fat meal before and after taking 110 mcg of selenium yeast per day for 10 days. There was no placebo group in the study. The meals contained an especially toxic—but common—fat byproduct called a lipid hydroperoxide (LH) which forms when natural polyunsaturated fatty acids overheat during manufacture, cooking, or frying. LH can attach to low-density lipoprotein (LDL, the "bad" cholesterol) in the blood, damage (oxidize) cells on arterial walls, and form the plaque that doctors believe leads to hardening of the arteries, a type of atherosclerosis.

Immediately before, and three hours after each meal, researchers measured blood-fluid (plasma) levels of selenium, antioxidants, LH-LDL, and an unstable compound that results from oxidized fat called malondialdehyde, or MDA. After the first meal, LH-LDL levels increased 2% and MDA levels increased 10%. After taking selenium yeast for 10 days and eating the second high-fat meal, levels of LH-LDL and MDA did not increase significantly. Researchers noted that throughout the study, plasma levels of selenium were adequate, and did not change significantly, and concluded that supplementing with selenium to adequate levels reduces risk for chronic and degenerative diseases such as atherosclerosis.

Oat fiber lowered cholesterol and risk for heart and blood-vessel disease, according to the results of a new study from the Department of Food Science and Nutrition, University of Minnesota, Saint Paul.

Researchers recruited 75 healthy, non-smoking men and women, aged 22 to 65, with total cholesterol levels of 200 mg per deciliter of blood (mg/dL) or more, a level which doctors say is the beginning of high risk for heart and blood-vessel disease. Participants took 6 grams of concentrated oat beta-glucan twice per day at morning and evening meals, or a placebo, for six weeks. Doctors measured weight, blood pressure, and blood fats at the beginning of the study, and after three and six weeks. The researchers asked participants to maintain the usual diet and physical activity, and to keep a diet diary for three days at three and six weeks, which doctors analyzed for nutrients.

At the end of the study period, low-density lipoprotein—LDL, the "bad" cholesterol—and total cholesterol had both dropped by 0.3 millimoles per liter (mmol/L) of blood in the beta-glucan group, a change doctors said was equal to or greater than a 12% decrease in heart and blood-vessel disease risk. There were no significant changes in the placebo group.

The beta glucan group did report some increase in intestinal gas. Oat beta-glucan is a water-soluble fiber that digests in the large intestine and produces these gases as well as short-chain fatty acids that doctors believe help lower cholesterol. The study authors suggested that oat beta-glucan would make a good standalone cholesterol-reducing dietary supplement, and that food manufacturers could add the ingredient to recipes to increase dietary fiber.

Reference: Nutrition Journal: March, 2007; Vol. 6, No. 6.