Plant Sterols

Marye Audet
phytosterols

Current research has shown that plant sterols, which are also called phytosterols, can reduce your risk of heart disease. By eating generous amounts of fruits, vegetable, and whole grains you may even be able to significantly lower your cholesterol.

What are Plant Sterols?

Sterols are naturally occurring substances that are found in all plants. When vegetables, or other produce, are eaten the sterols block the absorption of cholesterol in the small intestine.

Natural plant sterols have been proven to reduce dietary cholesterol. The research has been accepted by nationally recognized organizations such as the National Cholesterol Education Program and the American Dietetic Association. There have been over 140 clinical studies proving the value of sterols in a plan to reduce cholesterol. The Food and Drug Administration (FDA) has approved the health claims of the effectiveness of sterols in the diet as a way to reduce blood cholesterol.

How do Sterols Work?

The body gets cholesterol from only two places; diet and production of its own cholesterol. Once the cholesterol is in the digestive system it is absorbed into the cells lining the intestinal tract and taken by the blood to the liver.

Plant sterols imitate cholesterol and compete with dietary cholesterol in the intestine. Since the body cannot tell the difference between the two, it will absorb either one. It doesn't need plant sterols so it returns them to the intestine and they are discarded. Therefore less cholesterol is absorbed by the body overall. Since less real cholesterol is absorbed, over time this results in a reduction of blood cholesterol levels.

The sterols lower the low density cholesterol by 6 to 15 percent. Low density cholesterol, or LDL, is the type that causes the problems associated with high cholesterol levels. Sterols do not lower the high density cholesterol, or HDL, levels. High density cholesterol is the type that your body needs to function correctly.

How to Get Enough Sterols

The current recommendation is that sterol containing foods should be eaten twice a day. Since sterols occur naturally in very low levels it can be almost impossible to get the recommended amounts through whole foods like fruits and vegetables. In fact it would take over 100 pounds of produce or nuts to get a mere two grams of sterols.

Therefore, manufacturers have begun to add phytosterols to other foods like margarine, mayonnaise, and snack bars. This helps you to get the recommended 0.8 grams of sterols per day.

Side Effects and Interactions with Medicines

Phytosterols do not interfere with medications that are aimed at controlling cholesterol. They do, however, interact with a few other medications. Always talk to our doctor or pharmacist about possible drug interactions.

  • Beta carotene should be taken at a different time of the day than sterols. Sterols can keep the body from absorbing the beta carotene properly.
  • Ezetimibe/Simvastatin (Vytorin) can inhibit the body's absorption of plant sterols.
  • Sterols can also inhibit the absorption of vitamin E and should be taken at a different time.

There are also a few side effects that have been reported among users of sterols. These side effects are not usually dangerous. Among them are:

  • Nausea
  • Heartburn.
  • Constipation
  • Diarrhea
  • Decreased sex drive in men
  • Erectile dysfunction

The sexual side effects may stem from the fact that sterols have a plant hormone similar to estrogen that works against testosterone. These side effects were noted in men that were being treated for enlarged prostate.

There have been no serious side effects from the use of plant sterols reported. There is always the potential for an allergy to show up. Symptoms of allergic reaction would be:

  • Hives
  • Rash
  • Swelling
  • Difficulty breathing

If you experience any of these symptoms after taking phytosterols call your doctor or go to the emergency room.

Other Uses for Phytosterols

While most of the research on sterols is being done in the area of lowering blood cholesterol, some people are taking sterols for other medical problems. Some of these are:

  • Gallstones
  • Enhancing sexual performance
  • Immune system support
  • Treating colds and flu
  • Asthma
  • Relieving the symptoms of menopause
  • Helping control hair loss or baldness
  • Relieving the symptoms of an enlarged prostate

There has been some evidence that sterols can help to relieve the symptoms of enlarged prostate but do not reduce the size of the prostate itself. There is no research proving that sterols have an effect on any of the other problems.


Plant sterols may be a natural way to help lower cholesterol when combined with a healthy diet and moderate exercise.

Plant Sterols