Phytosterols

What are phytosterols?

Phytosterols, which include plant sterols and stanols, are plant-derived lipids similar to cholesterol.

Name origin: from the Greek phyt = a plant.

Foods Rich in Phytosterols

Foods naturally rich in phytosterols include unrefined sesame and corn oil, rice bran oil, whole grains, sunflower seeds, Brussel’s sprouts, rye bread, nuts and legumes ^[2].

Examples of foods enriched with plant sterols and stanols: certain spreads, margarines, low-fat yogurt, low-fat milk, low-fat cheese, dark chocolate, salad dressings and orange juice ^[1].

Phytosterols Function

Phytosterols decrease the absorption of cholesterol in the intestine ^[1].

Phytosterols Supplements

Non-prescription oral phytosterol supplements containing beta-sitosterol without prescription are available.

Phytosterols Benefits

The minimal intake of phytosterols that can have beneficial health effects is about 1 g/day and the maximal effect can be achieved by about 2-3 g/day ^[1,8]. Consuming foods naturally high in phytosterols rarely provides more than 0.5 g phytosterols per day ^[1]. 1 tablespoon of phytosterols-enriched margarine can provide 1.3 g of phytosterols ^[2].

Phytosterols in doses about 2 g/day are EFFECTIVE in:

• Decreasing total and LDL cholesterol and triglycerides in individuals with increased cholesterol levels ^[1,4,5,10]. Daily intake of 2 grams of phytosterols was associated with 10% decrease of LDL levels, in average ^[1,5,8,9]; intake greater than 2-3 g/day has not been associated with further LDL decrease ^[1]. Cholesterol-lowering effect was sustained for up to 85 weeks ^[9]. In individuals on statin therapy (to lower LDL cholesterol), phytosterols in doses 2-3 g/day can further decrease LDL levels by up to 10% ^[1].

There is INSUFFICIENT EVIDENCE about the effectiveness of supplements containing beta-sitosterol in prevention or treatment of benign prostate hyperplasia ^[1] or cancer ^[1].

There seems to be NO EVIDENCE about phytosterols intake and decreased risk of cardiovascular disease (coronary heart disease, stroke) ^[6,7].

Phytosterols Safety: Toxicity, Side Effects

Phytosterols added to foods and ingested at doses up to 3 g/day are Generally Recognized As Safe by the U.S. Food and Drug Administration (FDA) ^[3]. Still, these supplements are not recommended for pregnant and breastfeeding women, since their safety in these periods has not been tested.

Side effects may include nausea, indigestion, diarrhea and constipation ^[1].

Who should avoid phytosterols?

Individuals with a rare genetic disease sitosterolemia should avoid foods with added phytosterols in order to prevent premature atherosclerosis (hardening of the arteries) ^[1].