Phytosterols – Natural Allies Against Cholesterol?

Phytosterols are plant sterols and stanols, chemicals which are similar to cholesterol in terms of their structure. They can be found in cell membrane of the plants and they have an important role in human nutrition as they possess beneficial effects on health, especially in lowering the cholesterol levels in blood.

Phytosterol sources

Phytosterols can be found in many plant species and a lot of products are enriched by those plants. Some of them are:

Natural sources:

• Herbal oils (sunflower oil, corn oil, soya oil, turnip oil)
• Nuts and seeds
• Legumes
• Whole grains
• Vegetables and fruits (in smaller quantities)

Enriched products:

• Margarine, yoghurt and milk

Considering that food ensures only 200 to 400 milligrams per day and that the visible effects require 1.5 to 3 grams per day, appropriate supplementation is developed, mostly in shape of capsules and pills. Of course, it is more desirable to correct the nutrition first and then turn to supplements.

Effects of phytosterols on health

The first association with the phytosterol effects is the fact that they lower the LDL levels in blood. It is assumed that their main mechanism of action is based on competitive inhibition of cholesterol absorption in the gut. The effect was recorded in various populations, including the ones with normal and the ones with raised levels of cholesterol. Some research indicates that the intake of 2 to 3 grams of phytosterols per day can lover the LDL cholesterol level by 7 to 10 per cent within a few weeks, while the HDL level (“the good cholesterol”) stays unchanged.

Besides that, the phytosterols show anti-inflammatory effects and they support the immune system. It is considered that they might even inhibit the cancer cell growth (especially in breast cancer, prostate cancer and colon cancer).

Additionally, they are used in cosmetics because of their moisturizing and regenerative properties for the skin. Their influence on lipid metabolism is still being researched, as is the potential benefit in improving insulin sensitivity and glucose level regulation, which would be useful for diabetes.

Safety and side effects

Even though the phytosterols are mostly considered safe, there is a possibility for them to interfere with the absorption of the fat-soluble vitamins (vitamins D, E, K and A). With that, they must not be consumed by the people with sitosterolemia, genetic disease which makes cholesterols and phytosterols to accumulate in the body.

Despite the many health benefits, the limited absorption in the human body and the need for increased bioavailability pose a challenge in their use.

Overall, phytosterols pose a promising category of bioactive compounds with potential use in prevention and treatment of chronic diseases, but the further research is needed for the complete understanding of their effects and their optimal use.

Translated by Lea Malezan