Efficacy of flavonoids on biomarkers of type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

Abstract

A systematic review and meta-analysis of 28 randomized controlled trials (RCTs) to assess the efficacy of flavonoids intake on key biomarkers related to Type 2 diabetes mellitus was conducted. The mean difference (MD) with 95% confidence intervals (95% CI) was pooled using a random-effects model. Significant reduction in fasting glucose (MD: −0.22, 95% CI: −0.34 to −0.09, p = 0.0013), hemoglobin A1c (HbA1c) (MD: −0.26, 95% CI: −0.46 to −0.05, p = 0.021), homeostasis model assessment of insulin resistance (HOMA-IR) (MD: −0.40, 95% CI: −0.66 to −0.15, p = 0.0039), triglyceride (TG) (MD: −0.13, 95% CI: −0.21 to −0.05, p = 0.002), total cholesterol (TC) (MD: −0.14, 95% CI: −0.21 to −0.08, p = 0.0002), and low density lipoprotein-C (LDL-C) (MD: −0.15; 95% CI: −0.24 to −0.07, p = 0.0009) were observed in intervention group compare to placebo at the end of trial. Moreover, flavonoid intake had negative but non-significant effect on insulin (MD: −0.46), 2 h-postprandial glucose (2 h-PPG) (MD: −0.22), homeostasis model assessment of β-cell function (HOMA-β) (MD: −2.81), and insignificantly increased high-density lipoprotein-C (HDL-C) (MD: 0.03). In conclusion, flavonoid intake has modest but statistically significant benefits in glucose metabolism, insulin sensitivity, and lipid metabolism, especially for significantly lowing fasting blood glucose, HOMA-IR, HbA1c, TG, TC, and LDL-C.

Keywords:

• Biomarkers
• flavonoids
• meta-analysis
• randomized controlled trials
• type 2 diabetes mellitus

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The author(s) reported there is no funding associated with the work featured in this article.