Dietary Phytosterols and Human Aortic Valve

Atherosclerosis, Hypercholesterolemia

Atherosclerosis, Plant sterols, Plant stanols, Aortic valve

This randomized controlled double-blind intervention study unravels influence of dietary plant sterols and stanols on the structure and the sterol composition of the human aortic valve. The study patients will include 50-60 voluntary patients from the Helsinki Univ. Central Hospital, who will undergo aortic valve surgery. The patients will be randomized into plant sterol (E), plant stanol (A) and control (C) groups. Patients in the E and A groups will be asked to consume daily 2 grams plant sterols or plant stanols, respectively, in a margarine product.

High level of serum cholesterol is a risk factor for atherosclerotic complications, including atherosclerotic aortic valve disease. Over 50 years dietary plant sterols have been used to inhibit intestinal cholesterol absorption and to decrease its levels in serum. Daily human diet contains numerous different plant sterols, of which sitosterol and campesterol are the most abundant ones. Few epidemiologic studies suggest that sitosterol and campesterol may also be involved in formation of atherosclerotic changes in human arteries. The saturated forms of sitosterol and campesterol, i.e., the plant stanols (mainly sitostanol and campestanol) are beneficial with this respect. As part of daily diet, the plant stanols decrease absorption of both cholesterol and plant sterols, and thus, are putatively even more effective in prevention of atherosclerosis than the respective plant sterols. Our double-blind controlled intervention study unravels influence of dietary plant sterols and stanols on the structure and the sterol composition of the human aortic valve. 50-60 patients, who will undergo aortic valve surgery, will be asked to volunteer our study. The patients will be randomized into three groups: (A) a group consuming margarine containing daily 2 grams plant stanols, (E) a group consuming margarine containing daily 2 grams of plant sterols, (C) a control group consuming margarine without any plant sterols or stanols. The dietary intervention will last for 4 to 8 weeks from the randomization to the operation. Serum samples for analyses of serum lipids, lipoproteins and sterols will be collected at the randomization and at the operation. The atherosclerotic aortic valve will be examined with respect to its composition of cholesterol, other sterols and stanols. The aim of our study is to elucidate the effects of dietary consumption of plant sterols and stanols on the sterol composition and structure of the atherosclerotic disease-affected aortic valve in human patients.

Finland