Royal jelly (RJ) may contribute to glycemic control and liver function through various mechanisms. The present study aimed to quantify the effect of RJ supplementation on these outcomes. A literature search of Web of Science, Scopus, and PubMed/Medline, was conducted for RCTs investigating the efficacy of RJ on plasma liver enzymes and glycemic indices. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated for net changes using a random-effects model. Ten RCTs were selected for inclusion in this meta-analysis. Combined estimate of effect sizes for the impact of RJ on neither the plasma liver enzymes nor the glycemic indices were statistically significant. Subgroup analysis showed a significant reduction of serum FPG in trials with intervention duration ≥ 8 weeks (WMD: -4.28 mg/dl, 95% CI -7.41 to -1.14 mg/dl, p = 0.007), and those conducted in non-healthy populations (WMD: -4.28 mg/dl, 95% CI -7.41 to -1.14, p = 0.007). RJ does not significantly affect liver function and glycemic profile of adult population. In trials with longer intervention and those conducted in non-healthy populations a significant reduction of serum FBG was observed. This meta-analysis should be repeated in the future, with more primary articles included, in order to provide conclusive results.

Background: Dietary acid load seems to be associated with psychological disorders through several mechanisms, and may barricade their treatment and recovery. The aim of current study was to evaluate the relationship between dietary acid load, using potential renal acid load (PRAL) and dietary acid load (DAL) scores, with the severity of depression and anxiety among Iranian adults. Methods: A total of 6531 participants aged 35–65 years were recruited in this cross-sectional study. A validated food frequency questionnaire (FFQ) was used to assess dietary intakes of participants. DAL was estimated using PRAL and DAL scores. Depression and anxiety were screened using Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). Results: In the fully adjusted model, women with the highest DAL or PRAL had higher odds of more severe depression compared to those in the lowest category (OR = 1.20; 95% CI = 1.03–1.42 and OR = 1.20; 95% CI = 1.03–1.39, respectively). No significant association was observed between DAL and PRAL and depression severity in men and in the population as a whole. Regarding the association between PRAL and anxiety severity, there was no significant association when separated by sex. However, in the fully adjusted model for the whole population, participants in the highest tertile of PRAL had 13% greater odds of more severe anxiety than the lowest tertile (OR: 1.13, 95% CI: 1.01–1.13). No significant association was observed between DAL and anxiety severity in women, men or in the whole population. Conclusion: Women, but not men, with higher dietary acid load had significantly higher odds of having more severe depression. A significant positive association was also observed between dietary acid load and anxiety in the whole population.