The Effect of Cranberry Consumption on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Background: The aim of this paper, which includes a meta-analysis, is to elucidate the effects of cranberry consumption on systolic and diastolic blood pressure based on all relevant randomized controlled trials (RCTs). Materials and Methods: A systematic literature search was performed across the ISI Web of Science, PubMed, Embase, the Cochrane Library, and Google Scholar databases, encompassing trials published until December 2024. Weighted mean differences (WMD) were calculated using random or fixed-effects models. Between-study heterogeneity was evaluated using Cochrane's test and the I & sup2; index. This study's registration number in PROSPERO is CRD420251028424. Results: A total of 1204 publications were reviewed, leading to the inclusion of 12 trials for qualitative synthesis and meta-analysis. The pooled effect size indicated statistically nonsignificant reductions of 1.31 mmHg for systolic blood pressure (SBP) (p = 0.19) and 1.31 mmHg for diastolic blood pressure (DBP) (p = 0.12). Stratified analysis showed that the reduction in SBP was statistically significant in studies where cranberry was provided in juice form, with a duration of 8 weeks or less, involving participants with a mean age of < 50 years, and predominantly in females. Furthermore, subgroup analysis indicated a significant reduction in DBP in studies that involved both genders, lasted more than 8 weeks, included participants with a normal body mass index, and had a mean age below 50 years. Conclusion: This systematic review and meta-analysis suggest that cranberry consumption was not effective in managing SBP and DBP.