Plant sterols

While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

  • 3-Beta-stigmast-5-en-3-ol, (3beta)-stigmast-5-en-3-ol, 22,23-dihydrostigmasterol, 24-beta-ethyl-delta-5-cholesten-3beta-ol, 24-ethyl-cholesterol, a-dihydrofucosterol, alpha-dihydrofucosterol, alpha-phytosterol, a-phytosterol, Azuprostat®, beta-sisterol, beta-sitostanol ester, beta-sitosterin, beta-sitosterol, betasitosterol, beta-sitosterol glucoside, beta-sitosterol glycoside, beta-sitosterolin, brassicastanol, brassicasterol, B-sitosterol 3-B-D-glucoside, B-sitosterolin, campestanol, campesterol, cinchol, cupreol, delta-5-stigmasten-3beta-ol, ergostanol, ergosterol, phytostanol ester, phytostanols, plant stanol ester, plant stanols, plant sterol ester, plant sterols, quebrachol, rhamnol, sitostanol, sitosterin, sitosterin delalande, sitosterol, sitosterolins, sitosterols, soy sterol ester, stanol, stanol ester, sterinol, sterol, sterol esters, sterolins, stigmastanol, stigmasterol.

Background

  • Phytosterols, also called plant sterols, are a group of chemicals that occur naturally in plant-based foods such as fruits, vegetables, soybeans, breads, peanuts, peanut products, olive, flaxseed oil, and tuna.

  • Beta-sitosterol is one of the most common dietary phytosterols and is classified as a noncholesterol sterol, or neutral sterol. However, it is structurally similar to cholesterol and is the main sterol in the Western diet.

  • Margarines enriched with phytosterol have been marketed for their cholesterol-lowering effects. The U.S. Food and Drug Association (FDA) has authorized the use of labeling health claims for foods containing plant sterols and plant stanol esters. Sitosterols are also used in products for the treatment of other health disorders, including, but not limited to, benign prostatic hyperplasia (BPH), and for immune stimulation. However, more research is needed on the use of plant sterols for these conditions in humans.

Scientific Evidence

Uses

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

High cholesterol

Well-designed studies have demonstrated that supplementation of beta-sitosterol in the diet decreases total serum cholesterol and low-density lipoprotein (LDL) cholesterol.

Benign prostatic hypertrophy (BPH)

Some evidence suggests that phytosterols may be useful to treat symptoms of BPH. Further research is needed in this area.

Hair loss

Limited evidence suggests that a combination of plant compounds, including beta-sitosterol, may be helpful for hair loss in men and women that is due to genetic and environmental factors. Higher-quality studies are needed.

HIV

Beta-sitosterol and beta-sitosterol glucoside have been studied in combination for the treatment of HIV. The results are inconclusive. Further research is needed.

Immune system regulation

Beta-sitosterol and beta-sitosterol glucoside have been studied for their effects in decreasing immunosuppressive responses caused by strenuous exercise. The results are inconclusive. Further research is needed.

Rheumatoid arthritis

Beta-sitosterol and beta-sitosterol glucoside have been studied as a possible treatment for rheumatoid arthritis. The results are inconclusive. Further research is needed in this area.

Tuberculosis

Beta-sitosterol and beta-sitosterol glucoside have been studied for the adjunct treatment of tuberculosis. The results are inconclusive. Further research is needed in this area.

Gallstones

Limited evidence suggests that plant sterols may have a negative effect in individuals with gallstones. More research is needed.

*Key to grades:

Tradition

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

  • Allergies, Alzheimer’s disease (AD), antibiotic, antibiotic absorption problems in the gut, anti-inflammatory, antimalarial, antioxidant, antipyretic, asthma, blood thinner, bronchitis, cancer, chronic fatigue syndrome, cicatrizant (scar formation), common cold, coronary heart disease, diabetes mellitus, diarrhea (bloody), eczema, emetic (induces vomiting), enhanced athletic performance, estrogenic effects, fibromyalgia (muscle and connective tissue pain), headache, hepatitis, herpes, high blood pressure, influenza, menopausal symptoms, prostatitis, sexual dysfunction, skin conditions, stress, systemic lupus erythematosus (SLE), thrombocytopenia (low blood platelets), urinary tract disorders, venereal disease.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

  • For benign prostatic hypertrophy, one capsule, standardized to 20 milligrams of beta-sitosterol and 0.2 milligrams of beta-sitosterol glucoside, has been taken by mouth three times daily for up to six months.

  • For HIV, one capsule, standardized to 20 milligrams of beta-sitosterol and 0.2 milligrams of beta-sitosterol glucoside, has been taken by mouth three times daily for at least six months.

  • For high cholesterol, tablets, margarine, bars, dairy products, oil, orange juice, and salad dressings enriched with 0.3-9 grams of phytosterols have been taken by mouth daily for up to six months. Esterified or unesterified stanols, hydrogenated derivatives of sterols, have been taken by mouth, at 0.7-5.1 grams daily, for up to 12 weeks. Also, 1.2-2.1 grams of plant sterols, in combination with meat products (enriched with the minerals potassium, calcium, and magnesium), has been taken by mouth daily for three weeks. A combination of plant sterols and stanols (one gram each as esters or 1.5 grams of sterols plus 0.5 grams of stanols as esters) has been taken by mouth for three weeks. Beta-sitosterol has been taken by mouth at doses of 6-18 grams daily.

  • For immune system regulation, one capsule, standardized to 20 milligrams of beta-sitosterol and 0.2 milligrams of beta-sitosterol glucoside, has been taken by mouth three times daily.

  • For rheumatoid arthritis, one capsule standardized to 20 milligrams of beta-sitosterol and 0.2 milligrams of beta-sitosterol glucoside has been taken by mouth three times daily for 24 weeks.

Children (under 18 years old)

  • For high cholesterol, 1.5-3.0 grams of plant stanols has been taken by mouth daily for up to three months. Also, 1.2 grams of plant sterols have been taken by mouth daily for 26 weeks, and 2.3 grams of plant sterols has been taken by mouth daily for four weeks.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

  • Avoid with known allergy or hypersensitivity to plant sterols or stanols, or to plant sources from which plant sterols or stanols are isolated (e.g., pine, soy).

Side Effects and Warnings

  • Plant sterols may cause constipation, diarrhea, erectile dysfunction, loss of sexual desire, nausea, neurotoxic effects, and weight gain.

  • Plant sterols may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary

  • Plant sterols may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.

  • Use cautiously in patients with asthma or other lung diseases, primary biliary cirrhosis (liver disease), neurodegenerative disorders (such as such as ALS, parkinsonism, dementia, and Alzheimer’s disease), gallstones, diverticular disease, short bowel syndrome (and in those on tube feeding), celiac disease, sitosterolemia, ileostomy, or immune disorders, or in those taking agents to treat any of these conditions or hormonal agents.

  • Avoid in pregnant or breastfeeding women, due to a lack of scientific data.

  • Avoid in patients with advanced breast cancer treated with tamoxifen.

  • Avoid with known allergy or hypersensitivity to plant sterols or stanols, or to plant sources from which plant sterols or stanols are isolated (e.g., pine, soy).

Pregnancy and Breastfeeding

  • Avoid in pregnant or breastfeeding women, due to a lack of scientific data.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

  • Plant sterols may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

  • Plant sterols may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

  • Because sterols contains estrogen-like and antiestrogen-like chemicals, the effects of other agents believed to have estrogen-like properties may be altered.

  • Plant sterols may also interact with acarbose, acid-labile antibiotics, activated charcoal, agents that affect the immune system, anticancer agents, antidiarrheals, antiemetics, antiobesity agents, antituberculosis agents, antivirals, carbamazepine, chenic acid, chenodeoxycholic acid, cholesterol-lowering agents, cholestyramine, colestipol, C-reactive protein-reducing agents, cyclooxygenase inhibitors, diosgenin, drugs for benign prostate hyperplasia, drugs for erectile dysfunction, drugs for the skin, ezetimibe, fibrate, finasteride and alpha1-blockers, high-lipase pancreatin, hormonal agents, laxatives, lifibrol, neurologic agents, NMDA receptor antagonists, rifampin, Secholex®, statins, and tamoxifen.

Interactions with Herbs and Dietary Supplements

  • Plant sterols may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

  • Plant sterols may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

  • Because sterols contain estrogen-like and antiestrogen-like chemicals, the effects of other agents believed to have estrogen-like properties may be altered.

  • Plant sterols may also interact with acarbose, almonds, alpha-tocopherol (vitamin E), anticancer herbs and supplements, antidiarrheals, antiemetics, antiobesity herbs and supplements, antioxidants, antituberculosis herbs and supplements, antivirals, beta-lactoglobulin tryptic hydrolysate (LTH), carotenoids (such as beta-carotene), cholesterol-lowering herbs and supplements, C-reactive protein-reducing herbs and supplements, cyclooxygenase inhibitors, fat-soluble vitamins, fiber, fish oil, herbs and supplements for benign prostate hyperplasia, herbs and supplements for erectile dysfunction, herbs and supplements for the skin, herbs and supplements that affect the immune system, hormonal herbs and supplements, konjac (glucomannan), laxatives, lecithin, low-fat and low-cholesterol diets, minerals, neurologic herbs and supplements, NMDA receptor antagonists, olestra, soy, taurine, and vegan diets.

Author Information

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  1. Doornbos AM, Meynen EM, Duchateau GS, et al. Intake occasion affects the serum cholesterol lowering of a plant sterol-enriched single-dose yoghurt drink in mildly hypercholesterolaemic subjects. Eur J Clin Nutr 2006;60(3):325-333. View Abstract
  2. Ellegard L, Sunesson A, Bosaeus I. High serum phytosterol levels in short bowel patients on parenteral nutrition support. Clin.Nutr. 2005;24(3):415-420. View Abstract
  3. Gerber GS. Phytotherapy for benign prostatic hyperplasia. Curr Urol Rep 2002;3(4):285-291. View Abstract
  4. Gylling H, Pyrhonen S, Mantyla E, et al. Tamoxifen and toremifene lower serum cholesterol by inhibition of delta 8-cholesterol conversion to lathosterol in women with breast cancer. J Clin Oncol 1995;13(12):2900-2905. View Abstract
  5. Hallikainen MA, Sarkkinen ES, Gylling H, et al. Comparison of the effects of plant sterol ester and plant stanol ester-enriched margarines in lowering serum cholesterol concentrations in hypercholesterolaemic subjects on a low-fat diet. Eur J Clin Nutr 2000;54(9):715-725. View Abstract
  6. Homma Y, Ikeda I, Ishikawa T, et al. Decrease in plasma low-density lipoprotein cholesterol, apolipoprotein B, cholesteryl ester transfer protein, and oxidized low-density lipoprotein by plant stanol ester-containing spread: a randomized, placebo-controlled trial. Nutrition 2003;19(4):369-374. View Abstract
  7. Judd JT, Baer DJ, Chen SC, et al. Plant sterol esters lower plasma lipids and most carotenoids in mildly hypercholesterolemic adults. Lipids 2002;37(1):33-42. View Abstract
  8. Lau VW, Journoud M, Jones PJ. Plant sterols are efficacious in lowering plasma LDL and non-HDL cholesterol in hypercholesterolemic type 2 diabetic and nondiabetic persons. Am J Clin Nutr 2005;81(6):1351-1358. View Abstract
  9. Lee YM, Haastert B, Scherbaum W, et al. A phytosterol-enriched spread improves the lipid profile of subjects with type 2 diabetes mellitus–a randomized controlled trial under free-living conditions. Eur J Nutr 2003;42(2):111-117. View Abstract
  10. Martikainen JA, Ottelin AM, Kiviniemi V, et al. Plant stanol esters are potentially cost-effective in the prevention of coronary heart disease in men: Bayesian modelling approach. Eur J Cardiovasc Prev Rehabil 2007;14(2):265-272. View Abstract
  11. Noakes M, Clifton PM, Doornbos AM,et al. Plant sterol ester-enriched milk and yoghurt effectively reduce serum cholesterol in modestly hypercholesterolemic subjects. Eur J Nutr 2005;44(4):214-222. View Abstract
  12. Ntanios FY, Homma Y, Ushiro SA. A spread enriched with plant sterol-esters lowers blood cholesterol and lipoproteins without affecting vitamins A and E in normal and hypercholesterolemic Japanese men and women. J Nutr 2002;132(12):3650-3655. View Abstract
  13. Seki S, Hidaka I, Kojima K, et al. Effects of phytosterol ester-enriched vegetable oil on plasma lipoproteins in healthy men. Asia Pac J Clin Nutr 2003;12(3):282-291. View Abstract
  14. Williams CL, Bollella MC, Strobino BA, et al. Plant stanol ester and bran fiber in childhood: effects on lipids, stool weight and stool frequency in preschool children. J Am Coll Nutr 1999;18(6):572-581. View Abstract
  15. Yoshida M, Vanstone CA, Parsons WD, et al. Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes. Eur J Clin Nutr 2006;60(4):529-537. View Abstract

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.