The Effect of Anthocyanin Supplementation on Pro-Inflammatory Biomarkers in Patients With Metabolic Disorders: A Grade-Assessed Systematic Review and Meta-Analysis

Abstract

Introduction and Aim

Patients with metabolic disorders benefit from using anthocyanins. Nevertheless, the findings drawn from extant trials remain contentious. Thus, this meta-analysis evaluated anthocyanin's effect on inflammatory biomarkers in patients with metabolic disorders.

Materials and Methods

We comprehensively searched electronic databases, including PubMed, Scopus, Web of Science, and CENTRAL, from their inception to June 14, 2024.

Findings

A total of 11 randomized controlled clinical trials with 14 arms were analyzed. There was no significant effect of anthocyanin supplementation on interleukin (IL)-1β levels (standardized mean difference [SMD] = –0.01, 95% CI: –0.33, 0.31; P = 0.941, I² = 62.4%, P = 0.031), tumor necrosis factor-α (TNF-α) (SMD = –0.49, 95% CI: –1.07, 0.09; P = 0.098, I² = 94.0%, P < 0.001) and IL-6 (SMD = –0.69, 95% CI: –1.45, 0.06; P = 0.073, I² = 95.2%, P < 0.001), respectively. A significant between-study heterogeneity was identified, which was reduced when subgrouping by sample size, dosage, and study population. However, subgroup analysis showed that it might decrease TNF-α and IL-6 in patients with hypertension, and if the intervention lasted less than 12 weeks.

Conclusions

There was no significant impact of anthocyanin supplementation on IL-1β, TNF-α, and IL-6; however, it should be noted that the intervention has a decreasing impact on individuals with hypertension. Our observed effect sizes on IL-1β, TNF-α, and IL-6 are not clinically important.