Evaluating the effect of garlic extract on serum inflammatory markers of peritoneal dialysis patients: a randomized double-blind clinical trial study.

Background: Garlic can be considered as a useful natural herb in inhibition of inflammation. The aim of this study was to assess the effectiveness of garlic extract in lowering inflammatory markers in peritoneal dialysis (PD) patients.

Methods: In this parallel-designed double blind randomized clinical trial, 42 PD patients at the Shafa dialysis center, Tehran in 2017 were included. The primary outcome in this study was systemic inflammation which was evaluated by measuring the concentrations of IL-6 and CRP and ESR in serum.

Results: Baseline versus after-intervention median (IQR) of IL-6 (pg/ml), CRP (mg/L) and mean ± SD of ESR (mm) in garlic and placebo groups was 2.2 (0.8, 6.4) versus 0.7 (0.6, 1.2) (p <  0.001) and 2.0 (0.8, 2.1) versus 0.6 (0.6, 0.8) (p = 0.002), 13.0 (5.0, 14.0) versus 2.0 (1.0, 9.0) (p <  0.001) and 7.0 (2.0, 10.0) versus 6.0 (3.7, 7.5) (p = 0.547) and 35.4 ± 21.7 versus 50.7 ± 28.5 (p = 0.021) and 46.0 ± 26.0 versus 45.3 ± 22.3 (p = 0.797). Median (IQR) of Percentage Before-After change in CRP was - 71.4%(- 85.7, - 42.9%) and - 20.0%(- 30.0, 114.3%) in garlic and placebo group respectively. The Mann-Whitney U test indicated this difference is statistically significant (p <  0.001).

Conclusion: The results imply that administrating 400 mg of standardized garlic extract twice a day for 8 weeks resulted in a significant reduction in IL-6, CRP and ESR. Since inflammatory state can be a serious life threatening condition in PD patients, we suggest prescribing this safe and well-tolerated natural substance to attenuate the inflammatory state in these patients. However, assessment of these effects in a larger randomized trial is strongly recommended (IRCTID: IRCT2017072535305N1, 2017-10-16).