This site is intended for health professionals only

Evidence for the cholesterol lowering effects of plant stanol esters

Due to the potential of foods with added plant stanol esters to have a beneficial effect on blood cholesterol concentrations, a number of medical authorities have described their value in the treatment and management of elevated cholesterol. This report from The British Nutrition Foundation examines the evidence.

The British Nutrition Foundation is a registered charity. It promotes the wellbeing of society through the impartial interpretation and effective dissemination of scientifically-based knowledge and advice on the relationship between diet, physical activity and health.

The BNF wishes to thank McNeil Nutritionals Ltd for financial support in the publication and dissemination of the finished report.

You can view a PDF of the report here

About plant stanols and sterols

Although plants usually only contain a small amount of fat, their seeds are relatively concentrated sources. Interest in one particular group of plant-derived lipids, plant stanols and sterols, has developed in relation to their potential beneficial health effects, particularly in respect to cardiovascular disease.

Sterols are essential components of cell membranes, with a key role in controlling membrane fluidity and permeability. They are present naturally in small quantities in many fruits, vegetables, nuts, seeds and legumes.

Stanols are saturated sterols. They occur in similar sources such as nuts, seeds and legumes but in smaller quantities than sterols.

To improve their solubility, stanols and sterols are often combined with a fatty acid ester to produce plant stanol and sterol esters and it is in this form that is often added to food products.

The structure of plant stanols and sterols is very similar to that of cholesterol. It is thought that including plant stanols and sterols into the diet inhibits the absorption of both dietary cholesterol and the cholesterol incorporated into bile salts in the liver, therefore having the effect of lowering blood cholesterol levels. 

Total and LDL cholesterol levels are lowered without affecting HDL concentrations. Approximately 30-60% of total cholesterol is absorbed from the intestine into the blood; however, when plant stanol and sterol esters are present, absorption of cholesterol falls to approximately 20%. The reduction of LDL cholesterol alone ranges between 6% and 15%. Lowering blood total and LDL cholesterol levels may have the beneficial effect of reducing coronary heart disease risk.

Studies suggest that consuming approximately 2-3g of plant stanols or sterols each day is required to achieve cholesterol-lowering effects. The low concentrations contained in foods are often not great enough to acquire this amount through dietary means alone and therefore manufacturers have taken to fortifying foods, such as spreads, yogurts and yogurt drinks, with plant stanol or sterol esters.

When consumed regularly, and as part of a healthy, varied and balanced diet, foods and drinks with added plant stanol or sterol esters may bring about a reduction in LDL cholesterol concentration of up to 15%. Thus they may be a useful addition to a healthy diet for individuals wishing to reduce their blood cholesterol levels.