Research into the effects of raspberry on blood pressure and lipid profiles is inconclusive. This meta-analysis was aimed to determine whether raspberry has beneficial effects in clinical practice and to what extent these effects are associated with blood pressure and lipid profiles. A systematic literature search up to September 2023 was completed in PubMed/Medline, Scopus, and Web of Science, to identify eligible RCTs. Heterogeneity tests of the selected trials were performed using the I 2 statistic. Random effects models were evaluated based on the heterogeneity tests, and pooled data were determined as weighted mean differences with a 95% confidence interval. Eleven randomized controlled trials (with 13 arms) were eligible for this meta-analysis. Our findings revealed that Raspberry consumption had no significant effects on the blood pressure and lipid profile markers, including systolic blood pressure (SBP) (WMD, -0.37 mm Hg; 95%CI: -2.19 to 1.44; p = .68), diastolic blood pressure (DBP) (WMD, -2.14 mm Hg; 95%CI: -4.27 to 0.00; p = .05), total cholesterol (TC) (WMD, -6.83 mg/dL; 95%CI: -15.11 to 1.44; p = .10), triglycerides (TG) (WMD, -5.19 mg/dL: 95%CI: -11.76 to 1.37; p = .12), low-density lipoprotein-cholesterol (LDL-C) (WMD, -5.19 mg/dL; 95%CI: -11.58 to 1.18; p = .11), and high-density lipoprotein-cholesterol (HDL-C) (WMD, 0.82 mg/dL; 95%CI: -1.67 to 3.32; p = .51), compared to control groups. Subgroup analysis showed that raspberry consumption significantly decreased total cholesterol and LDL-C levels in people with elevated TC levels, metabolic syndrome, and andropause symptoms, as well as those older than 35, while the consumption of raspberries led to a significant increase in HDL-C levels in females, obese, under 35, and healthy individuals. Raspberry can improve lipid profile and blood pressure, but it is important to keep in mind that further research is necessary to fully understand the exact mechanism of action and a definite conclusion in this regard.
Pomegranate juice (PJ) has a possible anti-inflammatory effect because of its polyphenol content and antioxidants. However, the anti-inflammatory effect of PJ in randomized controlled trials (RCTs) has not been consistent. A previous meta-analysis conducted in 2016 reported a nonsignificant lowering effect of PJ on C-reactive protein (CRP) levels. This systematic review and meta-analysis aim to update the pooled effect size of PJ supplementation on CRP levels in RCT studies. PubMed, Scopus, and Web of Science databases were comprehensively searched until July 2023. Eligible studies were found by screening, their relevant data was extracted, and a risk of bias assessment was performed. The pooled effect size was calculated using a random effect model as the weighted mean difference (WMD) with a 95% confidence interval. This systematic review included 11 studies with 13 effect sizes and 696 participants. Meta-analysis showed that PJ supplementation led to a significant decrease in CRP levels compared to control groups (WMD: -2.55 mg/L; 95%CI: -3.44 to -1.66; p < 0.001). Subgroup analysis demonstrated the significant reduction effect of PJ on CRP levels in studies conducted on the both sexes or only females as well as Iranian population, individuals with 40 years≤, type 2 diabetes, polycystic ovary syndrome, or trials that intervened with PJ dosage of <250 ml/day. Meta-regression and dose-response analysis reported a nonsignificant linear and nonlinear relationship between intervention characteristics (duration and dose of PJ) and CRP changes. The current meta-analysis revealed that PJ supplemantation has a beneficial effect in improving CRP levels. It is recommended to understand this effect better, and find the optimal dose and duration of PJ supplementation to reduce CRP levels in the blood, and repeat meta-analysis after related RCTs are available. For the final proof of these effects, more detailed human studies are needed.
BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.
Fatty Acids , Glycemic Index , Adult , Humans , Randomized Controlled Trials as Topic , Liver
