Sterols & Stanols

What are sterols and stanols?

Sterols are a group of naturally occurring compounds that are part of all animal and plant cell membranes. Hydrogenating the sterol molecule forms stanols, which are found less abundantly in nature. This type of hydrogenation does not form trans fats, unhealthy fats known to raise cholesterol.

Both sterols and stanols are structurally similar to cholesterol, yet sterols and stanols are not synthesized by the body and are minimally absorbed by the intestines. Researchers have discovered that, because of their similarity in shape, they compete with cholesterol for absorption into our bodies, thereby blocking cholesterol from entering the bloodstream. This results in excretion of cholesterol from the body and a net reduction in blood levels of total and LDL “bad” cholesterol.

When eaten in recommended quantities as part of a low-fat diet, both sterols and stanols have been shown to lower total cholesterol up to 10% and LDL or “bad” cholesterol up to 14 to 17%.

How can I include sterols and stanols in my diet?

Sterols and stanols are present in small quantities in many fruits, vegetables, nuts, seeds, cereals, legumes, and other plant sources. However, the amount of sterols and stanols present in the average North American diet is low – around 250 milligrams per day. Even vegetarians, who tend to consume more plant foods, consume less than 1,000 milligrams on average.

For significant cholesterol reduction, you must consume 1,300-3,400 milligrams (1.3-3.4 grams) of sterols or stanols daily, respectively. It is virtually impossible to consume this quantity from foods without greatly exceeding your total fat and calories. See the chart below for products containing sterols and stanols.

Which is Better, Taking a Sterol or A Stanol?

Head to head trials comparing the LDL-lowering effect of sterols versus stanols have shown no significant difference between the two when consumed as part of a low-fat diet. Neither have an effect on blood levels of triglycerides or HDL “good” cholesterol.

The Food and Drug Administration (FDA) now allows foods to make specific claims if they contain the amount of sterols or stanols needed to effectively lower cholesterol. According to the FDA: “Scientific studies show that 1.3 grams per day of plant sterol esters or 3.4 grams per day of plant stanol esters in the diet are needed to show a significant cholesterol lowering effect. In order to qualify for this health claim, a food must contain at least 0.65 grams of plant sterol esters per serving or at least 1.7 grams of plant stanol esters per serving. The claim must specify that the daily dietary intake of plant sterol esters or plant stanol esters should be consumed in two servings eaten at different times of the day with other foods.”

Are Sterols and Stanols Safe to Consume on a Regular Basis?

No known negative health effects have been shown in research. The body’s tissues do not retain sterols or stanols and they do not affect the absorption of the fat-soluble vitamins A, D, E and K.

Talk to your doctor and/or registered dietitian if you have any questions about including sterols or stanols in your diet. In addition, do not use these products as a substitute for any prescription medications you are currently taking.

Food Sources of Sterols and Stanols

Plant sterols and stanols are found naturally in:

• Fruits
• Vegetables
• Nuts
• Seeds
• Cereals
• Legumes
• Vegetable oils (especially soybean oil, extra virgin olive oil and avocado oil)
• Rice bran
• Wheat germ (original, unprocessed)

Here are some other food sources rich in sterols:

Commercial Sources of Sterols and Stanols
Sterols and stanols are also available in higher quantities in commercially prepared table spreads and plant stanol ester dietary supplements.

information obtained from product websites

© Copyright 2008 The Cleveland Clinic Foundation. All rights reserved. rev. 12/06