Phytosterols

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.

Evidence Table

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. GRADE *
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. GRADE *


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

 A


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

 A


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

 B


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

 B


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.

 C


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.

 C


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

 C


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

 C


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.

 C


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.

 C


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.

 C


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.

 C


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.

 C


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.

 C


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

 D


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

 D
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. 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 healthcare provider. There may be other proposed uses that are not listed below.

Dosing

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.

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.

Interactions

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.

Attribution

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).

Bibliography

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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.
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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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.