Effect of Soybean on Bone Health and Some Metabolic Parameters in Postmenopausal Egyptian Women

Introduction: Great concern has been raised recently concerning the therapeutic impact of soybean. The present study aims to investigate the effects of soybean on bone health and metabolic parameters in postmenopausal women. Methods: In this clinical study, 72 healthy postmenopausal women aged between 45-65 years were given soybean bioactive fraction 2 capsules (500mg each) daily for 24 weeks. Each capsule contained 31.25 mg proteins, 3.2 mg carbohydrates and 4.84 mg isoflavones. Blood pressure, bone mineral density, plasma osteocalcin (OCN), telopeptides of collagen type I (CTX), fasting insulin and blood glucose, lipid profile, serum creatinine, alanine transaminase (ALT), aspartate transaminase (AST), and TSH were assessed prior and after the period of the study. Insulin resistance was calculated by homeostatic model assessment-IR formula (HOMA-IR). Results: Soy ingestion resulted in a significant increase in T score of the hip and OCN; recording -1.97±0.13/-1.76±0.12 and 22.44±0.60ng/ml/30.93±0.57ng/ml before/after treatment, respectively. A marked decrease was also detected in CTX from 2.22±0.10ng/ml to 1.48±0.08ng/ml. With regard to metabolic parameters, there was a significant decrease in fasting insulin (5.40±0.62uU/ml vs 4.15±0.45uU/ ml), however, fasting glucose and HOMA-IR showed no significant alterations. Lipid profile displayed remarkable decline in total cholesterol (188.86±7.23mg/dl vs 159.60±4.72mg/dl, triglycerides (97.09±5.23mg/dl vs 83.56±4.27mg/dl), LDL-c (75.60±3.06mg/dl vs 63.95±1.86mg/ dl) accompanied with a significant elevation in HDL-c (53.09±0.88 vs 65.81mg/dl±0.80mg/ dl). A significant decrease in both TSH (1.97±0.13 uIU/ml vs 1.40±0.08 uIU/ml) and serum creatinine (0.82±0.02mg/dl vs0.77±0.02mg/dl) was also noticed. Conclusion: Consumption of soy improves bone health, reduces cardiovascular risk with no adverse effects on kidney, liver or thyroid functions.