July 15/Washington/Hindustan Times -- They might be known for lowering bad cholesterol and reducing heart disease risk, but plant sterols have their own health risks, say researchers.

The researchers found that these compounds may accumulate in heart valves and lead to stenosis, abnormal narrowing in blood vessels.

Aortic valve stenosis (AS) is caused due to accumulation of cholesterol in the valve between the left ventricle and aorta, which impedes the flow of blood and puts extra pressure on the heart.

Nearly 2% of individuals over 65 and over 5% of those over 85 have AS, and as the population ages, it is becoming an increasing problem.

Plant sterols can block the absorption of dietary cholesterol into the body, and as such, high vegetable diets and/or plant sterol supplements are often used to alleviate high cholesterol.

The team led by Satu Helske collected blood samples from 82 patients with severe AS and aortic valves from 21 individuals undergoing valve surgery.

They found that non-cholesterol sterols, including plant sterols, can accumulate in aortic valves and at levels that directly related to their blood concentration.

These findings suggest that beneficial plant sterols may end up becoming a risk factor for AS.

From the July 21, 2008, Prepared Foods e-Flash