NEW YORK (Reuters Health) - Snacking on cocoa-flavored bars enriched with phytosterols can significantly reduce cholesterol levels, a new study shows.

Phytosterols are plant-derived compounds that are structurally similar to the cholesterol found in mammals. Foods containing phytosterols have been shown to help cut cholesterol, and the US Food and Drug Administration has endorsed these products "as part of a dietary strategy to reduce the risk of coronary heart disease," Dr. John A. Polarus of the University of California at Davis and colleagues write in the November issue of the Journal of the American Dietetic Association.

But concerns have been raised, they add, that these foods could reduce levels of certain fat-soluble vitamins and antioxidants in the blood in addition to cutting cholesterol.

To examine the effect of a food enriched with phytosterols on blood levels of cholesterol and nutrients, the researchers randomly assigned 67 people with high cholesterol to eat two snack bars containing 1.5 grams of plant sterols each every day for six weeks or two bars that did not contain plant sterols. The enriched bar, Cocoa Via Crunch, was made by Hackett town, New Jersey-based Master foods, which helped fund the research.

Study participants who ate the sterol-enriched bars had a 4.7- percent reduction in total cholesterol and a 6-percent reduction in LDL cholesterol after six weeks, and also showed an increase in the amount of HDL or "good" cholesterol in relation to total cholesterol.

While the sterol-enriched bars did not affect participants' blood levels of vitamins A or E, they did reduce beta-carotene levels. Making sure to get plenty of carotenoid-rich foods while using plant sterol-containing products could be enough to offset this reduction, the researchers suggest.

They conclude: "In conjunction with a healthful diet and regular exercise, the inclusion of a novel food product, such as a chocolate product that contains plant sterols, can be a safe and effective means to lower both total and LDL cholesterol levels."