Plant sterols (phytosterols)
Plant compounds structurally close to cholesterol that reduce its absorption in the gut, used in some "cholesterol-lowering" products.
Plant sterols (also called phytosterols, or plant sterols and stanols) are the “plant cousins” of cholesterol. Their very similar structure lets them compete with cholesterol for absorption in the gut: they take its place, reducing the amount of cholesterol absorbed.
The rare health claim that holds up: plant sterols carry an authorised health claim from the EFSA, one of the few scientifically recognised: at about 1.5 to 3 g a day, they lower LDL cholesterol by about 7 to 12%. This is a real, measurable effect, which sets them apart from many fanciful “cholesterol-lowering” claims.
This is why they are added to “cholesterol-lowering” products (enriched spreads such as Pro-Activ, drinking yoghurts). These products really do work at lowering LDL.
Important caveats to know about:
- Lower LDL does not mean proven fewer heart events: plant sterols lower the LDL figure, but evidence that they actually reduce heart attacks and strokes is lacking (and some studies raise questions about plant sterols building up in the arteries in some people). The effect on the “number” is clear, the effect on lasting cardiovascular health is less established
- They can reduce the absorption of carotenoids (beta-carotene, lycopene), which should be offset by eating plenty of fruit and vegetables
- Enriched products are often processed and expensive, and not essential if your diet is already rich in natural plant sterols
Natural sources: plant sterols are naturally present in vegetable oils, nuts (almonds, walnuts), seeds, pulses, wholegrains and avocado. A plant-rich diet provides them naturally (about 0.3 g a day on average, less than the “therapeutic” dose of enriched products).
In practice: for the general population, favour natural sources (plants, nuts) as part of a balanced diet. Products enriched with plant sterols can be a targeted tool for people with high cholesterol who want to bring it down, but within an overall strategy (fibre, omega-3, activity, less sugar and trans fats), and ideally with medical advice, rather than as an isolated miracle fix.