Beta-Sitosterol

Beta-sitosterol is the most abundant phytosterol found in plant-based foods, including vegetable oils, nuts, seeds, and legumes. Its molecular structure closely resembles cholesterol, allowing it to compete with dietary and biliary cholesterol for absorption in the intestinal lumen via the Niemann-Pick C1-Like 1 (NPC1L1) transporter. This mechanism reliably reduces LDL cholesterol by 5–15% when consumed at doses of 2–3 g per day, and has been endorsed by the FDA, EFSA, and multiple cardiovascular guidelines as an adjunctive dietary strategy. Beyond lipid management, beta-sitosterol has demonstrated efficacy in several randomized controlled trials for improving urinary symptoms associated with benign prostatic hyperplasia, likely through anti-inflammatory effects and inhibition of 5-alpha-reductase activity. It is generally well tolerated, though rare cases of sitosterolemia (a genetic condition causing excessive phytosterol absorption) represent a contraindication.