Plant sterols and cholesterol are compounds that have similar chemical structures but come from different sources. Plant sterols, also known as phytosterols are bioactive compounds found naturally in plant-based foods.
Phytosterols can be found in over 250 varieties and are present in various food sources. Vegetable oils such as corn, sunflower, soybean, and olive oil contain significant amounts of phytosterols. Additionally, almonds, wheat germ, wheat bran, passion fruit, orange, and cauliflower are also good sources of phytosterols.
While a typical diet contains about 300 mg of sterols and 30 mg of plant stanols, vegetarian diets can provide higher amounts, ranging from 300 to 500 mg per day. However, this quantity is considered small to achieve the recommended daily intake of phytosterols, which is around 2 g per day, for therapeutic effects on reducing LDL-cholesterol. Therefore, it is often necessary to consume foods enriched with phytosterols or use phytosterol supplements. Enriched processed foods like margarine, yogurt, and milk are available options.
Numerous studies have consistently shown that phytosterol-enriched foods can effectively reduce LDL-cholesterol levels. The primary mechanism behind this reduction is the decrease in cholesterol absorption in the intestines, which can range from 30% to 50%. Other proposed mechanisms include changes in gene expression related to cholesterol transport, decreased cholesterol esterification in the intestines, and increased cholesterol removal from the body.
Clinical studies have also demonstrated the cholesterol-lowering effects of plant stanols. For instance, consuming 2 g per day of plant stanols for 12 months resulted in an 11% reduction in LDL-cholesterol levels. Another study observed a 10.3% decrease in LDL-cholesterol levels after 4 weeks of consuming 4 g per day of plant stanols.
Recent meta-analyses have confirmed the cholesterol-lowering effects of phytosterols and compared the effects of sterols with stanols while evaluating the dose-response relationship.
Based on the reducing effect on LDL-cholesterol and absence of adverse effects, the European Atherosclerosis Society recommends the consumption of phytosterol-enriched foods in certain cases. These cases include individuals with hypercholesterolemia and low or intermediate cardiovascular risk, patients with high or very high cardiovascular risk who are not responding well to statins or are intolerant to them, and adults and children over 6 years old with familial hypercholesterolemia.
Most guidelines for dyslipidemia treatment and cardiovascular disease prevention recommend a daily intake of approximately 2 g of phytosterols along with lifestyle changes to achieve around a 10% reduction in LDL-cholesterol.
However, the relationship between phytosterol consumption and the risk of cardiovascular disease is not yet fully understood. Available evidence does not confirm cardiovascular protection from phytosterols, but it also does not indicate any harmful effects. Further studies, particularly long-term supplementation studies, are needed to provide more comprehensive insights.
0 Comments