INS and type 2 diabetes mellitus: Pooled estimates showed that resveratrol supplementation in patients with T2D lowered the levels of fasting glucose (SMD: −0.06 [95% CI: −0.24, 0.12]; I2 = 4%, p = 0.39) and insulin (SMD: −0.08 [95% CI: −0.50, 0.34], I2 = 73%, p = 0.002) when compared to those on placebo.