Plant sterols (phytosterols, phytostanols and their fatty acid esters) are cholesterol-like substances that occur naturally at low levels in fruits, vegetables, nuts and cereals.
When eaten at the recommended amount, between 2 and 3 grams a day, plant sterols can reduce low-density lipoprotein (LDL) cholesterol levels in our blood. Most people obtain between 150 and 360 milligrams of plant sterols daily, depending on diet.
Eating more than 3 grams per day does not reduce your LDL cholesterol any further.
Use in food
The Food Standards Code (Schedule 25 - Permitted Novel Foods) permits the use of plant sterols in margarine, low fat milks, low fat yoghurts and breakfast cereals, lower fat cheese and processed cheese.
Advice for pregnant women and children
Plant sterol-enriched foods are not unsafe for children but you should see a medical practitioner before feeding children these foods. These products have not been tested specifically in pregnant or lactating women but evidence about the way they work in the body suggests they are safe. Consult your doctor about using these products during or post pregnancy as there may be no need for you to reduce your cholesterol levels.
People with an extremely rare inherited metabolic disease called sitosterolaemia should avoid foods with added plant sterols. People with this condition absorb high levels of plant sterols which can lead to premature atherosclerosis and heart disease. There are only 45 reported cases of sitosterolaemia worldwide and all are managed strictly under medical supervision.
Plant sterols must be listed as an ingredient on the food label. If the manufacturer makes a claim about their benefits, the nutrition information panel on the label must also include the total amount of plant sterols added per serving and per 100 grams of food.