The effects of phytosterol and phytostanol supplementation on the lipid profile in postmenopausal women: A systematic review and meta-analysis of randomized controlled trials

Various studies have proven that phytosterols and phytostanols (PS) are lipid-lowering agents. These compounds play a role in regulating high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglyceride (TG) metabolism. Although various drugs are available and are currently used to treat dyslipidemia, the management of lipid abnormalities during the postmenopausal period remains a challenge. Thus, scientists are trying to develop new strategies to reduce serum lipids concentrations using natural products. However, the impact of PS administration on serum lipids in postmenopausal women remains unclear. Hence, the purpose of this study was to assess the effect of PS supplementation on the lipid profile in postmenopausal women based on a systematic review of the literature and a meta-analysis of randomized controlled trials. PubMed/Medline, Scopus, Embase, and Web of Science were searched to identify suitable papers published until January 18, 2022. We combined the effect sizes with the DerSimonian and Laird method using a random effects model. PS supplementation resulted in a significant decrease in TC (weighted mean difference [WMD]: -16.73 mg/dl) and LDL-C (WMD: -10.06 mg/dl) levels. No effect of PS supplementation on TG (WMD: -1.14 mg/dl) or HDL-C (WMD: -0.29 mg/dl) concentrations was detected. In the stratified analysis, there was a notable reduction in TC and LDL-C levels when the PS dose was ≥2 g/day (TC: -22.22 mg/dl and LDL-C: -10.14 mg/dl) and when PS were administered to participants with a body mass index ≥25 kg/m² (TC: -20.22 mg/dl and LDL-C: -14.85 mg/dl). PS administration can decrease TC and LDL-C, particularly if the dose of administration is ≥2 g/day and if the participants are overweight or obese. Further high-quality studies are needed to firmly establish the clinical efficacy of PS usage in postmenopausal females.