The Effects of Soy Products on Cardiovascular Risk Factors in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Clinical Trials

Previous studies have suggested that soy products may be beneficial for cardiometabolic health, but current evidence regarding their effects in type 2 diabetes (T2D) remains unclear. The aim of this systematic review and meta-Analysis was to determine the impact of soy product consumption on cardiovascular risk factors in patients with T2D. PubMed, Scopus, Embase, and the Cochrane library were systematically searched from inception to March 2021 using relevant keywords. All randomized controlled trials (RCTs) investigating the effects of soy product consumption on cardiovascular risk factors in patients with T2D were included. Meta-Analysis was performed using random-effects models and subgroup analysis was performed to explore variations by dose and baseline risk profile. A total of 22 trials with 867 participants were included in this meta-Analysis. Soy product consumption led to a significant reduction in serum concentrations of triglycerides (TGs) [weighted mean difference (WMD):-24.73 mg/dL; 95% CI:-37.49,-11.97], total cholesterol (WMD:-9.84 mg/dL; 95% CI:-15.07,-4.61), LDL cholesterol (WMD:-6.94 mg/dL; 95% CI:-11.71,-2.17), and C-reactive protein (WMD:-1.27 mg/L; 95% CI:-2.39,-0.16). In contrast, soy products had no effect on HDL cholesterol, fasting blood sugar (FBS), fasting insulin, glycated hemoglobin, HOMA-IR, systolic blood pressure (SBP) and diastolic blood pressure, or BMI (all P ≥ 0.05). In subgroup analyses, there was a significant reduction in FBS after soy consumption in patients with elevated baseline FBS (>126 mg/dL) and in those who received higher doses of soy intake (>30 g/d). Moreover, soy products decreased SBP in patients with baseline hypertension (>135 mm Hg). Our meta-Analysis suggests that soy product consumption may improve cardiovascular parameters in patients with T2D, particularly in individuals with poor baseline risk profiles. However, larger studies with longer durations and improved methodological quality are needed before firm conclusions can be reached.