October: Phytosterols and CAD

Phytosterols and Coronary Artery Disease: A Brief Overview
By: Nisa M.

Coronary artery disease is the most common cause of death in the United States. According to the most recent NHANES III, nearly 50% of Americans have borderline to high cholesterol (levels >200 mg/dL) (American Dietetic Association, Fact Sheet, 2000).
To combat these high cholesterol levels, it is recommended that persons eat a diet low in saturated fats and cholesterol, high in fruits, vegetables and whole grains. However, sometimes these dietary interventions are not enough to reduce cholesterol levels in all patients. For these individuals, medications, such as statins may be prescribed. Yet to still combat the alarming incidence of hypercholesterolemia, food manufacturers have jumped on the band wagon after learning of the benefits of phytosterols/stanols in reducing cholesterol. In 1995 the first phytosterol functional food product, Benecol® margarine, was launched in Finland, and since then phytosterol products have spread to more than twenty counties and they have emerged as one of the major types of functional foods (Moreau, R.A., 2003).

Phytosterols are cholesterol-like molecules found in all plant foods and are highest in vegetable oils (soybean, corn, etc.). They are absorbed only in trace amounts but also inhibit the absorption of intestinal cholesterol including recirculating biliary cholesterol, a key step in cholesterol elimination.. (Ostlund, R.E, 2002). Based on the proven cholesterol lowering ability of plant sterols, the ATP III has recommended that they be added (2g/day) as part of their therapeutic lifestyle changes in their dietary recommendations (Chan, Y. Varady, K., Yuguang, L., 2006). The following articles examine the role of phytosterols in reducing cholesterol.


References:
American Dietetic Association, Nutrition Fact Sheet, 2000.

Ostlund RE Jr. Phytosterols and cholesterol metabolism. Annual Review of Nutrition. 2002;22:533-49. Epub 2002 Apr 4.

Moreau, R.A. Plant sterols in functional foods. 2003. Book Chapter. P. Dutta (ed.), in Phytosterols as functional food components and nutraceuticals. Marcel Dekker, New York, pp. 317-345.


Article 1 (from the current ADA journal, page 1564):

Castro Cabezas M., de Vries J.H.M., Van Oostrom A.J.H.H.M., Iestra J., van Staveren W.A. Effects of a Stanol-Enriched Diet on Plasma Cholesterol and Triglycerides in Patients Treated with Statins. Journal of the American Dietetic Association- 2006 10 (Vol. 106, Issue 10). http://www.adajournal.org/article/PIIS0002822306016981/fulltext


This article examines the effects of combining phytosterols in combination with statin therapy to further improve the cholesterol lowering properties of both methods. The subjects were randomly selected and were divided into two groups: intervention (received stanol margarine and intensive dietary intervention) and the control ( received control margarine and an educational pamphlet on healthy eating.) Both groups were educated and were expected to self monitor their triglycerides for the 6 weeks. The groups also filled out a FFQ and had a visit with a R.D. Only the intervention group received individualized dietary counseling. The results of the study showed a significant reduction in LDL cholesterol in the intervention group with no other significant effects on triglycerides or weight. This study supports previous findings that stanols can reduce TC and LDL cholesterol by 10 percent.


Article 2:
Ostlund R.E. Jr., Phytosterols and cholesterol metabolism. Annual Review of Nutrition. 2002;22:533-49. Epub 2002 Apr 4. Department of Internal Medicine, Washington University, St Louis, Missouri
Also appeared in: Current Opinion in Lipidology. 2004 Feb;15(1):37-41.

This article examines the method of action of phytosterols, their effects, and the the future direction for the use of phytosterols in nutrition. Phytosterols inhibit cholesterol from intestinal absorption, reducing the pool of absorbable cholesterol. Phytosterol esters dissolved in food fat reduce LDL-cholesterol by 10% at a maximum effective dose of 2 g/day. Single meal studies have shown that phytosterols in intact foods are bioactive at doses as low as 150 mg. The potential effectiveness of phytosterols has been improved in several ways. Individuals most likely to benefit from phytosterols have been identified as having high cholesterol absorption and low cholesterol biosynthesis. Phytosterols can also be added to low fat and non fat foods when emulsified with lecithin which can further aid in reducing overall dietary fat intake. The review also supported the use of phytosterols as they effectively reduce LDL-cholesterol when given as supplements, and the smaller amounts in natural foods also appear to be important contributors to improving cholesterol levels. Future areas for exploration are also discussed including the addition of food sterol amounts to nutrient databases for better tracking.