Many products on the market, from yogurt to margarine, are marketed as heart healthy options due to the addition of plant sterols. It is understandable to question whether these claims have merit. The question is whether plant sterols are something you should consider adding to your diet to help control your cholesterol levels, or whether this is just clever marketing.
Plant Sterols
Plants have compounds that are chemically related to cholesterol. The two main groups of these compounds are sterols, also called photosterols, and stanols, or photostanols. Plant sterols are a cousin of cholesterol. Along with stanols, plant sterols do for a plant what cholesterol does in the human body: help to make hormones, vitamins and the outer layer of cells.
Cholesterol
Cholesterol is a type of fat wrapped in proteins. It is created in the body by the liver, as is ingested in some foods. Some cholesterol is necessary for health; it helps the brain as well as other organs in the body to function properly. There are two types of cholesterol, HDL, high-density lipoprotein, commonly called the 'good' cholesterol, and LDL, low-density lipoprotein, the 'bad' cholesterol. Cholesterol is carried in the blood. When there is too much, it starts to build up on the blood vessel walls. This can eventually lead to a heart attack or stroke.
Plant Sterols Affects on Cholesterol
Once consumed, plant sterols work to lower cholesterol by preventing the body from efficiently absorbing cholesterol from food, according to Harvard Health Publications, a newsletter published by the Harvard Medical School. The liver requires cholesterol in digestion, so when no new cholesterol is available from food, it takes LDL cholesterol from the blood, leaving the HDL cholesterol. This is important because LDL cholesterol carries cholesterol from the liver through the bloodstream, increasing the risk of cholesterol buildup on the blood vessel walls. HDL cholesterol works in the opposite way and carries cholesterol back to the liver where it can be broken down. So plant sterols help to lower the 'bad' cholesterol while leaving the 'good' cholesterol in your bloodstream.
Recommended Amounts
To lower your cholesterol by taking plant sterols the recommended amount is 2g daily, according to an article published in August 2003 in the "Mayo Clinic Proceedings." Studies have shown that a 2g dose of plant sterols a day reduces LDL cholesterol by 10 percent, the article concluded. This reduces the risk of heart attack or stroke by an average of 20 percent, according to the Harvard Medical School's Family Health Guide. Higher intakes of sterols do not have any greater effect. When plant sterols are consumed in addition to eating a diet low in cholesterol and saturated fat, LDL cholesterol levels may reduce by 20 percent. Adding plant sterols to a diet when on cholesterol lowering medication is more effective than doubling the medication dose.
References
- The Harvard Medical School Family Health Guide: Eating Your Way to Lower Cholesterol
- KidsHealth from Nemours: What's Cholesterol
- Harvard Health Publications: LDL Cholesterol: Foods fortified with sterols, stanols can lower cholesterol
- "Mayo Clinic Proceedings"; Efficacy and Safety of Plant Stanols and Sterols in the Management of Blood Cholesterol Levels; Efficacy and Safety of Plant Stanols and Sterols in the Management of Blood Cholesterol Levels; Martijn B. Katan, Ph.D., et. al.; August 2003
