Beta-glucans are soluble dietary fibers with well-known cardiometabolic benefits, but extraction methods significantly influence their molecular weight (MW), structural integrity, and physiological effectiveness. Understanding how extraction technology affects their properties and resulting clinical outcomes is essential for optimizing therapeutic use.

To systematically examine how beta-glucan extraction methods impact MW, structural features, and cardiometabolic health markers (such as lipid profile, blood sugar control, and blood pressure) in adults.

Following PRISMA 2020 guidelines, we searched SciSpace, PubMed, and Google Scholar through February 2026 for randomized controlled trials (RCTs) that studied beta-glucan interventions in adults, with reported extraction methods, MW data, and clinical outcomes. Two independent reviewers screened 966 records, evaluated 245 unique papers, and extracted data from 15 full-text articles meeting inclusion criteria. Primary outcomes included LDL cholesterol and total cholesterol; secondary outcomes included HDL cholesterol, triglycerides, fasting glucose, HbA1c, and blood pressure.

Fifteen RCTs ( n = 1847 participants) met the criteria. Hot water extraction preserved high MW ( > 500 kDa) and viscosity, while enzymatic hydrolysis lowered MW to 50–200 kDa. High-MW beta-glucans (3–6 g/day) consistently lowered LDL cholesterol (WMD: −0.31 mmol/L; 95% CI: −0.42 to −0.20; I ² = 45%) and total cholesterol (WMD: −0.38 mmol/L; 95% CI: −0.51 to −0.25; I ² = 52%) compared to control. Lower-MW preparations had smaller effects (LDL-C WMD: −0.15 mmol/L; 95% CI: −0.28 to −0.02). A dose-response relationship was confirmed, with 5–6 g/day of high-MW beta-glucan resulting in 12–15% LDL-C reductions. Postprandial glucose responses improved by 26–38% across all MW categories, but long-term glycemic control (HbA1c) remained unchanged in 8–12 week trials.

Extraction methods play a key role in determining beta-glucan MW and clinical effectiveness. Hot water extraction producing high-MW preparations (> 300 kDa) at doses ≥ 3 g/day reliably reduces LDL cholesterol through viscosity-dependent mechanisms. Standardized reporting of extraction procedures, MW, and viscosity is vital for clinical translation. Future studies should systematically compare extraction techniques, measure viscosity under physiologically relevant conditions, and include long-term cardiovascular endpoints to strengthen the evidence for regulatory and clinical guidance.