If you have high cholesterol levels, taking compounds such as beta-sitosterol can help lower the amount of cholesterol in your blood. Although your liver makes a certain amount of cholesterol, much of the cholesterol in your blood comes from the foods you eat. Beta-sitosterol is a chemical found in some plants that can help interfere with cholesterol absorption.
Beta-sitosterol and Plant Sterols
Beta-sitosterol is a chemical found in some plants which belongs to a family of substances known as plant sterols. Plant sterols have a chemical structure which is very similar to cholesterol, but they do not affect the body the same way as cholesterol. Consuming foods with beta-sitosterol and other plant sterols can interfere with the ability of the digestive tract to absorb cholesterol and thus lowers cholesterol levels in the body.
Mechanism
Cholesterol is transported from the digestive tract into the bloodstream using special proteins known as transporter proteins. These transporters recognize cholesterol by its chemical structure; substances with a similar chemical structure, such as beta-sitosterol, can also bind to these transporting proteins and keep them from moving cholesterol into the blood. If each day you consume 2 g of plant sterols or stanols, which are a related group of substances, your LDL or "bad" cholesterol levels will decrease by 5 to 15 percent, according to the National Heart Lung and Blood Institute.
Sources
Beta-sitosterol and other important sterols and stanols come from plant-based foods. You can get plant sterols and stanols from wheat germ, wheat bran, brussels sprouts, almonds and peanuts, although other fruits and vegetables also have small amounts of these compounds. Many vegetable oils, such as sesame, corn, canola and olive oil also have sterols and stanols. Because it is difficult to get 2 g per day from these food sources alone, some food products, such as tubs of margarine, orange juice, cereal and dairy products are now supplemented with beta-sitosterol and other sterols and stanols.
Safety
Most people can consume foods with beta-sitosterol without experiencing any severe side effects. Nausea, constipation, diarrhea, gas and indigestion are common side effects, and beta-sitosterol has also been linked to a loss of libido and erectile dysfunction. Beta-sitosterol is not safe for people with a rare genetic condition known as sitosterolemia, and this supplement may not be effective if you are taking cholesterol lowering medications such as ezetimibe or pravastatin.
