Effects of royal jelly consumption on inflammation and oxidative stress: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE: This systematic review and meta-analysis examines the impact of royal jelly (RJ) on inflammation and oxidative stress. By synthesizing existing research, it aims to provide valuable insights into the potential health benefits of RJ. MATERIALS AND METHODS: PubMed/Medline, Web of Science, and Scopus were searched until the end of December 2023. This meta-analysis included all randomized clinical trials assessing the effect of RJ supplements on serum levels of high-sensitivity C-reactive protein (hs-CRP), total antioxidant capacity (TAC), and malondialdehyde (MDA). A random-effects model was utilized to calculate the pooled mean differences (MD) and 95% confidence interval. RESULTS: Seven suitable datasets from 6 trials were considered eligible. RJ supplementation significantly reduced MDA (WMD, -1.79 (-3.00 to -0.58), p=0.004; I2 = 97.4%) and increased TAC (WMD, 0.98 (0.24 to 1.71), p=0.009, I2 = 98.5%), but it did not significantly change hs-CRP levels (WMD: -0.24; 95% CI: -0.60, 0.10; p=0.17). RJ supplementation in higher doses and in participants with normal body mass index (BMI) could induce a greater elevation in TAC, and in participants with normal BMI, a stronger reduction in MDA. CONCLUSION: Although this meta-analysis confirmed that RJ could be a useful intervention to reduce oxidative stress, this research should be updated in future due to the restricted number of trials.