Association between dietary acid load and blood pressure: A systematic review and meta-analysis

Existing research on the association between dietary acid load and blood pressure is not conclusive. This systematic review and meta-analysis aimed to combine findings of evidence regarding the association between dietary acid load and blood pressure.

MEDLINE and EMBASE databases were searched for studies published up to November 2016. Effect sizes of eligible studies were pooled using random-effects models. Heterogeneity was tested using Cochrane Q test. Subgroup analysis was done according to the method used for estimating dietary acid load.

Of 7033 papers, eight articles (seven cross-sectional and one longitudinal studies) were eligible for inclusion. Higher dietary acid load was associated with high systolic blood pressure (mean difference (MD)= 0.840 mm Hg, 95%CI:  0.043 , 1.637; I2=98.4%; p=039) and diastolic blood pressure ((MD)= 0.754 mm Hg, 95%CI:  0.273 , 1.235; I2=75.1%; p=002). Subgroup analysis showed that population type and sex for both of SBP and DBP and also basic blood pressure and age only for DBP were the potential sources of heterogeneity. 

Analysis suggests that high dietary acid load was associated with greater blood pressure. Further studies are needed to explore the precise impact of low dietary acid load on blood pressure in patients with hypertension.