Impact of soy milk consumption on cardiometabolic risk factors: A systematic review and meta-analysis of randomized controlled trials

Background: Soy milk contains some beneficial components such as isoflavones which can exert favorable effects on the cardiovascular health. The current study aimed to comprehensively evaluate the potential effects of soy milk consumption on cardiometabolic risk factors in adults. Methods: Relevant articles published up to June 2020 were systematically retrieved from SCOPUS, PubMed/ MEDLINE, EMBASE, and Web of Science databases. In our study, we included all the randomized controlled trials (RCTs) investigating the impact of soy milk consumption on various cardiometabolic risk factors in adults (age >= 18 years). A meta-analysis of the eligible studies was performed using the random-effects model. Results: The quantitative meta-analysis of 18 eligible RCTs (665 participants, age range 18-65 years) demonstrated that the consumption of soy milk significantly reduced systolic (P < 0.001) and diastolic (P = 0.002) blood pressure, total (P = 0.001) and low-density lipoprotein (P = 0.041) cholesterol, waist circumference (P = 0.005), C-reactive protein (P < 0.001), and tumor necrosis factor-alpha (P = 0.016). Significant between-study heterogeneity was found for the pooled effect sizes of blood pressure and low-density lipoprotein cholesterol. In addition, the subgroup analyses indicated that the decrease in systolic blood pressure (SBP) was more pronounced when soy milk was consumed for <= 4 weeks. However, there were no significant differences between soy milk and control groups for the other factors, namely body weight, body mass index (BMI), high-density lipoprotein cholesterol, triglycerides, fasting blood glucose (FBG), and fasting insulin, interleukin-6, and fibrinogen. Conclusions: The current systematic review and meta-analysis revealed that incorporating soy milk into the diet might favorably affect several cardiometabolic risk factors in both healthy and unhealthy individuals.