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Integrative, Alternative & Complementary Medicine, Second Edition

Stanols and Sterols

by EBSCO CAM Review Board

Category: Herbs and supplements

Related terms: Campestanol, 5-alpha-stanols, phytostanols, phytosterols, sitostanol, stanol esters, sterol esters, stigmastanol

Definition: Natural substances promoted as dietary supplements for specific health benefits.

Principal proposed use: Lowering cholesterol

Overview

Stanols are substances that occur naturally in various plants. Their cholesterol-lowering effects were first observed in animals in the 1950s. Since then, a substantial amount of research suggests that plant stanols (usually modified into stanol esters) can help to lower cholesterol in persons with normal or mildly to moderately elevated levels. Stanols are available in margarine spreads, salad dressings, and dietary supplement tablets. Related substances called sterols or phytosterols (such as beta-sitosterol) and sterol esters appear to lower cholesterol in much the same manner as stanols.

Sources

Sterols are found in most plant foods and occur naturally in wood pulp, tall oil (a by-product of paper manufacturing), and soybean oil. Stanols can also be manufactured from the sterols found in many foods. Stanol and sterol esters are manufactured by processing stanols or sterols with fatty acids from vegetable oils. Stanol-sterols and their esters are added to margarine spreads and salad dressings and are also available as dietary supplement tablets.

Therapeutic Dosages

Typical dosages of stanol-sterols and their esters to improve cholesterol profile range from 2.7 to 5.1 grams (g) per day. One study suggests that using stanol products once a day may be as effective as dividing up the intake throughout the day. It may take up to three months to show a substantial decrease in total cholesterol values.

Therapeutic Uses

Strong evidence suggests that stanol-sterols and their ester forms can significantly improve cholesterol profile. There are no other known medicinal uses of stanols or stanol esters. Phytosterols do offer additional potential benefits.

Scientific Evidence

Because they are structurally similar to cholesterol, stanols (and sterols) can displace cholesterol from the “packages” that deliver cholesterol for absorption from the intestines to the bloodstream. This displaced cholesterol is then excreted from the body. This action not only interferes with the absorption of cholesterol from food; it also has the additional (and probably more important) effect of removing cholesterol from substances made in the liver that are recycled through the digestive tract.

Numerous double-blind, placebo-controlled studies, ranging in length from thirty days to twelve months and involving more than one thousand people, have found that sterol-stanols and their esters are effective for improving cholesterol profile. The combined results suggest that these substances can reduce total cholesterol and LDL (bad) cholesterol by about 10 to 15 percent. They do not, however, have much of an effect on HDL (good) cholesterol or on triglycerides.

For example, in a double-blind, placebo-controlled study, 153 people with mildly elevated cholesterol were given sitostanol esters in margarine (at 1.8 or 2.6 g of sitostanol per day) or margarine without sitostanol ester for one year. The results in the treated group receiving 2.6 g per day showed improvements in total cholesterol by 10.2 percent and LDL cholesterol by 14.1 percent, significantly better than the results in the control group. Neither triglycerides nor HDL cholesterol levels were affected.

Fish oil too has been shown to have a favorable effect on fats in the blood, in particular triglycerides. A study investigating the possible benefit of combining sterols with fish oil found that together they significantly lowered total cholesterol, LDL cholesterol, and triglycerides and also raised HDL cholesterol in persons with undesirable cholesterol profiles.

Even people already taking standard medications to improve cholesterol profile (specifically, drugs in the statin family) appear to benefit when they use stanols-sterols as well. According to one study, persons who are on statins and who start taking sterol ester margarine too will improve to the same extent as if those persons doubled the statin dose. Stanols and sterols also appear to be safe and effective for improving cholesterol profile in people with type 2 diabetes.

Safety Issues

Sterols are presumed safe because they are found in many foods. Stanols are also considered safe, but for a different reason: They are not absorbed. No adverse effects have been reported in any of the studies on lowering cholesterol, with the exception of one study that reported mild gastrointestinal complaints in a few preschool children. In addition, no toxic signs were observed in rats given stanol esters for thirteen weeks at levels comparable to or exceeding those recommended for lowering cholesterol.

Although concerns have been expressed that stanol esters might impair absorption of the fat-soluble vitamins A, D, and E, this does not seem to occur at the dosages required to lower cholesterol. Stanol esters might interfere with the absorption of alpha-carotene and beta-carotene, although some studies have found no such effect. It is also not clear whether sterols or sterol esters impair nutrient absorption. Until more is learned, it may be reasonable for people using stanol or sterol products to also take multivitamin-multimineral tablets.

See also: Beta-sitosterol; Cholesterol elevation; Triglycerides, high

Further Reading

1 

Allen, R. R., et al. “Daily Consumption of a Dark Chocolate Containing Flavanols and Added Sterol Esters Affects Cardiovascular Risk Factors in a Normotensive Population with Elevated Cholesterol.” Journal of Nutrition 138 (2008): 725-731.

2 

Castro Cabezas, M., et al. “Effects of a Stanol-Enriched Diet on Plasma Cholesterol and Triglycerides in Patients Treated with Statins.” Journal of the American Dietetic Association 106 (2006): 1564-1569.

3 

Hendriks, H. F., et al. “Safety of Long-Term Consumption of Plant Sterol Esters-Enriched Spread.” European Journal of Clinical Nutrition 57 (2003): 681-692.

4 

Katan, M. B., et al. “Efficacy and Safety of Plant Stanols and Sterols in the Management of Blood Cholesterol Levels.” Mayo Clinic Proceedings 78 (2003): 965-980.

5 

O’Neill, F. H., et al. “Comparison of Efficacy of Plant Stanol Ester and Sterol Ester.” American Journal of Cardiology 96 (2005): 29-36.

6 

Plana, N., et al. “Plant Sterol-Enriched Fermented Milk Enhances the Attainment of LDL-Cholesterol Goal in Hypercholesterole-mic Subjects.” European Journal of Nutrition 47 (2008): 32-39.

7 

Woodgate, D., C. H. Chan, and J. A. Conquer. “Cholesterol-Lowering Ability of a Phytostanol Softgel Supplement in Adults with Mild to Moderate Hypercholesterolemia.” Lipids 41 (2006): 127-132.

Citation Types

Type
Format
MLA 9th
"Stanols And Sterols." Integrative, Alternative & Complementary Medicine, Second Edition, edited by Paul Moglia, Salem Press, 2020. Salem Online, online.salempress.com/articleDetails.do?articleName=CAM2e_0690.
APA 7th
Stanols and Sterols. Integrative, Alternative & Complementary Medicine, Second Edition, In P. Moglia (Ed.), Salem Press, 2020. Salem Online, online.salempress.com/articleDetails.do?articleName=CAM2e_0690.
CMOS 17th
"Stanols And Sterols." Integrative, Alternative & Complementary Medicine, Second Edition, Edited by Paul Moglia. Salem Press, 2020. Salem Online, online.salempress.com/articleDetails.do?articleName=CAM2e_0690.