Supermarket shelves are packed with a vast array of ‘cholesterol lowering' products. These products contain substances called sterols and stanols, touted as being able to lower cholesterol levels. But, what are they, and do they really work?
What are sterols and stanols?
The structure of sterols and stanols are similar to that of cholesterol. Therefore, when they travel through our digestive tract they compete with cholesterol, getting in the way and blocking it from being absorbed into the bloodstream. The result is that cholesterol is excreted from the body, therefore reducing our total and LDL cholesterol levels in the body.
When eaten as part of a low-fat diet, both sterols and stanols have been shown to lower total cholesterol by up to 10%, and LDL (bad) cholesterol by up to 14 - 17%.
Systematic reviews suggest that sterols and stanols reduce LDL cholesterol in those with normal or moderately raised cholesterol levels, and that this effect is directly related to the dose consumed.
One study carried out in 2004 looked at 72 people with mildly raised cholesterol levels. Participants were asked to consume 2g of sterol fortified orange juice each day. Following an 8-week period, researchers found that LDL cholesterol was reduced by an average of 12.4%.
What are the current recommendations?
The National Cholesterol Education Program recommends that those with high cholesterol should aim to get 2 grams of sterols or stanols every day for maximum cholesterol lowering effect.
It's also important to note that sterol and stanol fortified foods are not for everyone. They are only recommended for those who have been told by their doctor to lower their cholesterol or for those who have had a heart attack in the past.
Do foods naturally contain sterols or stanols?
Sterols and stanols are present in small quantities in many whole foods. These include:
- Rice bran
- Unprocessed wheat germ
- Vegetable oils (soybean oil, extra virgin olive oil and avocado oil)
Commercial brands of plant sterols and stanols are also available. These are normally in the form of margarine, yogurt, milk, fruit juice, and more recently in products such as granola bars etc.
Please do take care when choosing such fortified products - they are not calorie free and more is not necessarily better! They ought to be consumed as part of a healthy, low-fat diet and in the amounts recommended by manufacturers.
Some of the commercial brands available include:
- Benecol products
- Healthy Heart yoghurt
- Promise Activ Super Shots
- Take Control spreads
One of the major problems with foods fortified with sterols and stanols is that they tend to be very expense. Statistics suggest that they must be taken on a consistent basis before any cholesterol lowering effect can be seen.
Therefore, it is important to carefully consider the cost verses the health benefit prior to commencement, since infrequent consumption will not have the desired effect and will ultimately be a waste of your money.