Resveratrol supplementation reduces key inflammatory biomarkers, meta-analysis shows

• Meta-analysis of 17 randomized, controlled trials (736 participants)
• Resveratrol supplementation significantly reduces TNF-alpha and C-reactive protein
• Median dosage is 300 mg/day for 2 months

Summary

This meta-analysis was performed to assess the effect of resveratrol supplementation on the levels of inflammatory markers.

A literature search up to May 2017 was completed to identify clinical trials that assessed resveratrol effects on circulating (serum and plasma) inflammatory markers (interleukin [IL]-6, tumor necrosis factor-alpha [TNF-alpha], and high-sensitivity C-reactive protein [hs-CRP]) in adults.

Inclusion criteria included randomized, controlled clinical trials published in English language journals involving adults (with or without concurrent medications) and with sufficient information on inflammatory marker levels at baseline and study end for both resveratrol and control groups. Participants had to ingest resveratrol supplementation (purified resveratrol or resveratrol-enriched extracts) for at least one month but not more than 12 months.

Weighted Mean Difference (WMD) was used to evaluate changes in inflammatory markers between resveratrol treatment and control using fixed-effects or random-effects models. Heterogeneity was assessed using Higgins I-square (I²). Publication bias and subgroup analyses were also performed.

A total of 17 trials with 736 participants met the criteria and were included in the analysis. The mean participant age ranged between 36 and 70 years. All but one trial included from 19 to 20 patients. The remaining trial included 127 participants, mostly men (66%). Median resveratrol intake was 300 mg/day (range 6 to 800 mg/day) for a median duration of 2 months (range 1 to 12 months)

Results reveal significant reductions in the level of TNF-alpha (WMD: -0.44 pg/ml; 95% CI, -0.71 to -0.164; P=.002) and hs-CRP (WMD: -0.27 mg/l; 95% CI, -0.5 to -0.02; P=.033) after supplementation with resveratrol. By contrast, resveratrol supplementation had no significant effect on the level of IL-6 (WMD: -0.16 pg/ml; 95% CI, -0.53 to 0.20; P=.38).

The authors report significant heterogeneity for type of sample in IL-6 and study duration in inflammatory markers IL-6, TNF-alpha, and hs-CRP. No heterogeneity was found for the dose of resveratrol or type of disease. No publication bias was reported.

These findings suggest a protective effect of resveratrol supplementation on inflammation, particularly related to reducing the production of the inflammatory biomarkers TNF-alpha and hs-CRP levels, which may have clinical value in the management of patients with metabolic diseases.