The beneficial effect of tart cherry on plasma levels of inflammatory mediators (not recovery after exercise): A systematic review and meta-analysis on randomized clinical trials

• Published in: Complementary therapies in medicine Vol. 68; p. 102842
• Main Authors: Gholami, Ali, Amirkalali, Bahareh, Baradaran, Hamid Reza, Hariri, Mitra
• Format: Journal Article
• Language: English
• Published: Scotland Elsevier Ltd 01.09.2022; Elsevier Limited; Elsevier
• Subjects: Adult; Antioxidants; Biomarkers; Body mass index; C-reactive protein; C-Reactive Protein - analysis; Chronic illnesses; Clinical trials; Confidence intervals; Cytokines; Dietary Supplements; Exercise; Fruits; Health risks; Heterogeneity; Humans; Inflammation; Inflammation - metabolism; Inflammation Mediators; Interleukin 6; Interleukin-6 - metabolism; Interleukins; Intervention; Meta-analysis; Phytochemicals; Plasma; Plasma levels; Polyphenols; Proteins; Prunus avium; Prunus avium - metabolism; Randomized Controlled Trials as Topic; Recovery (Medical); Systematic review; Tart cherry; Tumor Necrosis Factor-alpha; Tumor necrosis factor-TNF; Tumor necrosis factor-α; Tumor necrosis factor-alpha; C-reactive protein; Prunus avium; Systematic review; Tart cherry; Interleukin-6; Meta-analysis
• ISSN: 0965-2299; 1873-6963
• DOI: 10.1016/j.ctim.2022.102842

Chronic inflammation has been classified as one of the most important threats to health. Scientists suggested that tart cherry (TC) can reduce plasma levels of inflammatory mediators. Therefore, the aim of this study was to summarize the effect of TC on circulating C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) among adult participants in non-exercise randomized clinical trials (RCTs). The eligible English-language RCTs were found by searching databases including PubMed, Web of Science, Cochrane Library, Scopus, and clinical Trials.gov up to May 2022, with no time limit. We used the mean change from baseline and its standard deviation for both intervention and comparison groups to calculate the effect size. The random-effects model proposed by DerSimonian and Laird was used to estimate the overall summary effect and the heterogeneity. We used PRISMA 2020 guidelines to report this study. Ten RCTs were included in this study. The results demonstrated that TC had a significant decreasing effect on plasma CRP level compared with the comparison group (weighted mean differences (WMD) = −0.55 mg/L; 95% confidence interval (CI): − 1.03, − 0.06; p = 0.029), but had no significant effect on plasma IL-6 compared with comparison group (WMD = 0.08 pg/mL; 95% CI: −0.02, 0.17; p = 0.10). The effect of TC consumption on plasma TNF-α level was evaluated in only three studies that showed no significant effects (p>0.05). Our results confirmed a significant decreasing effect of TC on CRP. Regarding IL-6 and TNF-α, our study did not present any significant effect of TC. [Display omitted] •Tart cherry significantly reduced plasma concentration of c-reactive protein compared with the comparison group.•Tart cherry did not reduce plasma concentration of interleukin-6 compared with the comparison group.•The effect of tart cherry on plasma levels of tumor necrosis factor alpha was evaluated in only two studies and both of them showed no significant effects.