The effect of high versus low adherence to the dash diet on blood pressure: a systematic review and meta-analysis

Objective: The objective of our study was to systematically review the current literature and perform a meta-analysis to evaluate the effect of the level of adherence to the DASH diet on blood pressure. Design and method: The identification of relevant studies, data extraction and critical appraisal of the included studies were performed independently by two reviewers. A random-effects model was employed to synthesize the available evidence using the standardized mean difference (SMD) as the appropriate effect size. Results: A total of 37 and 29 articles were included in the qualitative and quantitative analysis, respectively. The pooled effect for systolic blood pressure was SMD = -0.18 (95%CI: -0.32 to -0.04; I2 = 94%; PI: -0.93 to 0.57) and for diastolic blood pressure it was SMD = -0.13 (95%CI: -0.19 to -0.06; I2 = 94%; PI: -0.42 to 0.17). Conclusions: Our findings showed that greater adherence to the DASH diet has a beneficial effect on blood pressure compared to the lowest adherence. Increased compliance with DASH diet recommendations might also have a positive effect on cardiometabolic factors and overall health status. Future studies should aim to standardize the tools of adherence to the DASH diet and utilize rigorous study designs to establish a clearer understanding of the potential benefits of the level of adherence to the DASH diet in blood pressure management.