What do plant sterols do?
Plant sterols have a similar structure to cholesterol and they work by competing with it for absorption in the gut. This helps to lower the amount of total cholesterol absorbed.
As well as reducing the uptake of pre-formed cholesterol from your diet, plant sterols also block absorption of the cholesterol which is made in your liver and secreted into the gut via the bile.
It is the EFSA’s opinion that sterols and stanols at daily intakes of 1.5g to 3g can lower blood LDL-cholesterol by 7% to 12% and reduce the risk of coronary heart disease. Intakes of 3g can lower LDL by 11.3% within two to three weeks.1
Having too much cholesterol in the blood is not a disease in itself, but if cholesterol levels build up and deposits form in the artery walls, this can restrict the flow of blood to the brain, heart and other parts of the body, potentially leading to atherosclerosis (narrowing of the arteries) and increasing the risk of a stroke or heart attack.
A number of studies have shown plant sterols lower the levels of ‘bad’ LDL cholesterol. Multiple studies 2 revealed that people who drank phytosterols had a significant reduction in ‘bad’ cholesterol levels and their total cholesterol and blood pressure also decreased. 3
Using sterols with statins
Statin medications lower cholesterol through a direct effect on the liver. Because they work in a different way to plant sterols, the two can be used together to lower cholesterol levels even further. In fact, adding plant sterols to statin medication may be more effective than doubling the statin dose.
Researchers usually recommend against combining ezetimibe, a cholesterol-lowering drug which works in a different way to statins, with plant sterols. This is because they both work in a similar way, and plant sterols are unlikely to have any extra effect.4 But a 2017 small study by the University of Panama found patients with heart disease who used plant sterols combined with the ezetimibe, had lower LDL ‘bad’ cholesterol compared to the groups not using this combination.5
Getting plant sterols from your diet
Plant sterols can be found in small quantities in a range of foods such as whole grains, fruits, vegetables, nuts, cereals and vegetable oils.
Diet alone only provides a small amount of plant sterols (typically 150-400mg a day although around 50 per cent higher in vegetarians) though, far less than the 2-3g of sterols needed to have a cholesterol-lowering effect.6 As an alternative, try functional food products which have plant sterols added to them, including fortified margarines, cereals and yogurts, or take a daily supplement to boost your dietary intake.
Plant sterol safety
Plant sterols are considered safe to use for most people. Taking more than 3g per day is not recommended as there is no evidence of additional health benefits with larger amounts. There is also a possibility that higher doses may decrease absorption of some fat-soluble vitamins and carotenoids.
Plant sterols should not replace cholesterol-lowering medications prescribed by your doctor but can be used in addition.7
The correct dosage
There is currently no UK or EU recommended daily allowance. One tablet providing 800mg of plant sterols is the level shown to maintain normal cholesterol levels. To lower blood cholesterol, experts recommend taking three 800mg plant sterols tablets daily 8