Objective: Studies in experimental models of nonalcoholic fatty liver disease (NAFLD) have reported positive effects of soy components in improving metabolic parameters. Whether such effects could be achieved through consumption of whole soy foods in patients with NAFLD is still unclear. Therefore, this trial was conducted to assess the effects of soy milk on metabolic parameters of patients with NAFLD.
Methods: This parallel randomized clinical trial was conducted on 70 patients with NAFLD. Patients in the soy milk group consumed 240 ml of soy milk daily as a part of low-calorie diet (i.e., 500-deficit calorie diet) for 8 weeks. Patients in the control group just followed the low-calorie diet. Grade of fatty liver, liver enzymes, lipid profile, serum high-sensitivity C-reactive protein (hs-CRP), and anthropometric indices were measured at baseline and the end of the trial.
Results: At the end of the trial, the soy milk group had significantly higher reduction in serum alanine aminotransferase (ALT) (-12.06 ± 17.61 IU/L in the soy milk group versus -5 ± 8.58 IU/L in the control group, p = 0.04) and hs-CRP (-1.32 ± 1.60 mg/L in the soy milk group versus -0.36 ± 1.54 mg/L in the control group, p = 0.01) compared to the control group. However, changes in fatty liver grade and other liver enzymes, including aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase, as well as lipid profile and anthropometric indices were not significantly different between the treatment groups.
Conclusion: Consumption of soy milk in the context of a restricted-calorie diet for 8 weeks had favorable effects on serum ALT and hs-CRP in patients with NAFLD.
Keywords: Soy milk; alanine aminotransferase; high-sensitivity C-reactive protein; liver steatosis; nonalcoholic fatty liver disease.