Improvement of Triglyceride Levels through the Intake of Enriched-β-Conglycinin Soybean (Nanahomare) Revealed in a Randomized, Double-Blind, Placebo-Controlled Study

Soybean is recognized as a beneficial food with various functional components, such as β-conglycinin, which improves lipid metabolism. We evaluated the effects of the β-conglycinin-rich soybean Nanahomare on triglyceride (TG) levels. In this randomized, double-blind, placebo-controlled study, we divided 134 adult subjects into test and placebo groups that consumed processed food containing enriched-β-conglycinin soybean or low-β-conglycinin soybean. Hematological tests and body composition measurements were performed at weeks 0 (baseline), 4, 8, and 12 of the study period. TG levels significantly decreased in the test group compared with the placebo group at weeks 4 (change from baseline to week 4, placebo: 0.27 ± 44.13 mg/dL, test: -20.31 ± 43.74 mg/dL, p = 0.035) and 12 (change from baseline to week 12, placebo: -0.14 ± 65.83 mg/dL, test: -21.30 ± 46.21 mg/dL, p = 0.041). In addition, among subjects whose baseline TG levels were ≥100 mg/dL, the levels significantly improved in the test group at weeks 4 (p = 0.010) and 12 (p = 0.030), whereas the levels were not different between the test and placebo groups among those whose baseline levels were <100 mg/dL. These results suggest that the ingestion of enriched-β-conglycinin soybean improves serum TG levels.