What are plant sterols?

Plant sterols, also known as phytosterols, are naturally occurring substances in plant cell walls. They can help lower the cholesterol levels in the blood. Plant sterols lower a particular type of cholesterol called low-density lipoprotein (LDL) cholesterol. LDL cholesterol is also known as the "bad cholesterol" because it brings cholesterol to the blood vessels, where it builds up, increasing your risk of a heart attack or stroke.

How do plant sterols lower cholesterol? They block LDL cholesterol from being absorbed from your intestines into your bloodstream. This reduces the amount of LDL cholesterol in the blood so it does not clog up your blood vessels.

It's important to eat the right amount of foods with plant sterols. A typical Western diet contains only 0.2 to 0.4 grams of phytosterols per day. But experts recommend an intake of 2 grams of plant sterols per day to lower cholesterol. Since it may be difficult to reach this target with natural food sources like fruits, vegetables, nuts, seeds, and legumes alone, you can also consume plant-sterol-enriched foods or supplements.

Health Canada has approved the use of plant sterols as additives in many food products, such as margarines and juices. To find these products, look on the label for health claims such as "plant sterols help reduce cholesterol" or "plant sterols help lower cholesterol." You can also get plant sterols from dietary supplements.

How can I benefit from plant sterols?

If you have high cholesterol, you may be at risk of heart disease, which can lead to serious problems such as heart attack and stroke. But there are different types of cholesterol. Too much LDL (low-density lipoprotein) or "bad" cholesterol can cause fatty plaques to build up in your blood vessels, which increases your risk of heart disease.

There are many ways to lower your LDL cholesterol, including medications and healthy eating. There is also a natural way to lower LDL: eating plant sterols.

Plant sterols are naturally occurring substances in plant based foods. Plant sterols block cholesterol from the foods you eat from getting into your bloodstream. Eating about 2 grams of plant sterols per day has been shown to lower total and LDL cholesterol levels by about 5% to 15%.

If you are taking medications to lower your cholesterol and would like to try plant sterols, check with your doctor to see if your medication dose needs to be adjusted after you start eating plant sterols regularly. You should also check with your dietitian, doctor, or pharmacist about other diet changes that can help you control your cholesterol.

Where can I find plant sterols?

Plant sterols have shown to be effective at reducing LDL or "bad" cholesterol. High LDL cholesterol has a strong link to heart disease. This means that plant sterols can have a positive impact on your health. You can get plant sterols from food products and supplements.

Plant sterols are found naturally in foods such as vegetable oils, nuts, seeds, cereals, and legumes. In Canadian diets, vegetable oils are the richest natural sterol source.

You can also get plant sterols from fortified foods where plant sterols are used as ingredients. Fortified products include spreads, mayonnaise, margarine, salad dressing, yogurt and yogurt drinks, and vegetable and fruit juices. To find a fortified product, check the label for health claims such as "plant sterols help reduce cholesterol" or "plant sterols help lower cholesterol."

Another source of plant sterols is dietary supplements, which are available without a prescription.

Are fortified foods and supplements worth the price? Natural food products are often the cheapest alternative, but you would need to eat large amounts to get 2 grams per day of plant sterols (the amount recommended for lowering your cholesterol). Eating large amounts of oils and nuts also means that you will be getting too many calories and fats. Foods fortified with plant sterols are a bit more expensive, but it is easier to get 2 grams a day. Health Canada allows fortified foods to contain a maximum of 1 gram of plant sterols per serving.

There is no one best source for plant sterols. It all depends on your preferences for taste, cost, and convenience.

I am considering plant sterols. What next?

Are plant sterols for me?

There are a few questions to ask yourself to find out if plant sterols are right for you:

  1. Am I ready to commit to consuming plant sterols regularly?
    It will mean changes to your diet, so you may want to consult with a registered dietitian. When choosing foods, keep your allergies in mind - foods rich in plant sterols may also contain common ingredients such as nuts, soy, and gluten.
  2. Do I have any medical conditions?
    Check with your doctor before using plant sterols if you:
    • have a history of gallstones
    • have intestinal or bowel disease
    • have medical conditions affecting the brain, such as Parkinson's disease or Alzheimer's disease
    • have breast cancer and are taking tamoxifen
  3. Am I pregnant or breast-feeding?
    If so, check with your doctor before using plant sterols.

What to look for when grocery shopping

When you're in the grocery store, here's what to look for:

  • natural food products rich in plant sterols, such as:
    • cereals
    • legumes
    • nuts and seeds
    • vegetable oils
  • foods fortified with plant sterols (check the label to see if plant sterols have been added), such as:
    • spreads
    • mayonnaise
    • margarine
    • salad dressing
    • yogurt and yogurt drinks
    • vegetable and fruit juices

Plant sterol supplements are also available without a prescription. Consult with your physician, your pharmacist, or a registered dietitian.

How much do I need?

The National Cholesterol Education Program (in the United States) recommends a daily intake of about 2 grams of plant sterols to reduce LDL cholesterol by about 5% to 15%. Health Canada has set an upper limit of 3 grams of plants sterols a day for adults and 1 gram per day for children 5 years of age and older.

Are they safe?

Health Canada considers plant sterols to be safe as long as you do not consume more than the upper limit (3 grams a day for adults and 1 gram a day for children 5 and over). Plant-sterol-fortified foods are not recommended for pregnant and breast-feeding women or for children under 5 years of age because of other nutritional priorities. However, there are no safety concerns if these people do accidentally consume foods fortified with plant sterols. Speak with your physician if you are considering the use of plant sterols to lower your cholesterol.