The Effect of Soybean Lunasin on Cardiometabolic Risk Factors: A Randomized Clinical Trial

Abstract

Lunasin, a peptide isolated from soybeans, has been shown to exert antioxidant, anticarcinogenic, and hypocholesterolemic effects in animal and in vitro models. In a triple-blind, placebo-controlled crossover study, 31 participants (female: 19, male: 12, mean age 61 ± 9.9 years) were randomized to an 8-week treatment of lunasin-enriched soy extract (335mg/d) or placebo. A 3-week washout period was utilized between treatments. Serum lipids, glucose, and insulin, as well as blood pressure and anthropometrics, were measured at baseline, week 7, and week 8 of each treatment period. There were nonsignificant reductions in cardiometabolic risk factors with treatment: total cholesterol −0.1mmol/L, 95% CI [−0.28, 0.03]; LDL cholesterol −0.07mmol/L, 95% CI [−0.2, 0.06]; triglyceride 0% mmol/L, 95% CI (−10%, 11%]; fasting serum glucose −2% mmol/L, 95% CI [−4%, 1%]; BMI −0.05 kg/m2, 95% CI [−0.17, 0.07] and waist circumference −0.63cm, 95% CI [−1.8, 0.53]. Supplementation with lunasin-enriched soy extract for 8 weeks did not result in significant changes in serum lipids, glucose, insulin resistance, blood pressure, BMI, or waist circumference. Future studies should focus on a higher dosage, larger sample size, and/or longer treatment to determine the independent role of lunasin, if any, in the effect of soy on cardiometabolic risk factors.