Phytosterols are natural ingredients in food and can effectively reduce serum cholesterol levels and regulate inflammation. According to studies, cardiovascular disease is the first cause of morbidity and mortality worldwide. Among the major risk factors for cardiovascular disease are hyperlipidemia, elevated levels of cholesterol, triglycerides and other blood lipids.
What are phytosterols?
They are components of plant membranes and their structure is very similar to that of human cholesterol. Their name derives from the Greek words “plant” and “sterols” and the reason is that they are mainly found in plant foods. In particular, natural sources are vegetable oils, cereals, nuts and vegetables.
They are categorized into two main categories, sterols and stanols. Despite their abundance in food, only 10% of phytosterols can be absorbed from the intestine. For this reason, functional foods and food supplements have been made. The most common dietary phytosterol is sitosterol.
What are the effects of phytosterols?
The main action of phytosterols is that they inhibit the absorption of endogenous and exogenous cholesterol, thereby effectively reducing serum cholesterol levels.
Phytosterols are absorbed to a small extent by the intestine. However, as they have a similar chemical structure to human cholesterol, they are competing for absorption. As a result, cholesterol becomes insoluble and thus eliminates with stool.
Reduction of total cholesterol and LDL cholesterol
According to many clinical studies, phytosterols can lower total cholesterol and LDL cholesterol levels by lowering cardiovascular risk by up to 20%. Their action can be combined with other common anti-lipid drugs, such as statins, and have additional benefits.
Specifically, according to studies, the daily intake of 2 – phytosterols may reduce serum total and LDL cholesterol levels by an average of 10%, while similar results were seen in those already taking statins. For this reason, EFSA (European Foods Safety Authority) and FDA (Food and Drug Administration) have approved their use to reduce blood lipids and thus reduce the incidence of cardiovascular disease.
According to some preliminary studies, phytosterols may also affect the inflammatory response of the body. In particular, they seem to reduce the inflammatory activity of immune cells, including macrophages and neutrophils, by regulating inflammation mechanisms and relieving symptoms associated with numerous autoimmune diseases.
Sitosterols, a category of phytosterols, appear to play a role in managing and preventing the onset of cancer. It is reported that phytosterols can inhibit cancer in the lungs, stomach, ovaries and breasts, but more studies are needed to demonstrate their exact role and action in the body.
Benign prostatic hyperplasia
Benign prostatic hyperplasia (BPH) is the term used to describe a non-cancerous prostate enlargement. According to some studies, beta-sitosterol intake reduces inflammation and improves the symptoms of benign prostatic hyperplasia.
Phytosterols, both via supplements and via functional foods (milk, yoghurt and spreads), are safe and have no side effects. However, occasionally nausea, indigestion, diarrhea and constipation may occur, especially when taken for more than 12 months.
Dose of phytosterols
The recommended dose is 2-3 grams. equally divided into 1-3 doses within the day. Doses larger than 3g. do not offer additional benefits.
Phytosterol supplements are not recommended for sitosterolemia, pregnant women and nursing women.