Dietary acid load and risk of hypertension: A systematic review and dose-response meta-analysis of observational studies

Abstract

Background and aim: Previous studies have assessed diet-induced mild metabolic acidosis in relation to blood pressure, however, data are conflicting. Current systematic review and dose-response meta-analysis aimed to summarize earlier findings from observational studies on the association between dietary acid load and hypertension.

Methods and results: We searched the online databases for relevant publications up to Feb 2019, using relevant keywords. Overall, 14 studies (3 prospective and 11 cross-sectional studies) that included 306,183 individuals and 62,264 cases of hypertension were included in the current meta-analysis. Combining effect sizes from both prospective and cross-sectional studies revealed no significant non-linear association between dietary acid load (based on net endogenous acid production (NEAP) method) and hypertension. However, stratified analysis based on study design showed a significant non-linear association between dietary acid load and hypertension in prospective studies (P = 0.006), but not cross-sectional ones. According to linear dose-response analysis, no significant association was found between dietary acid load (based on NEAP) and hypertension (combined effect size: 1.01, 95% CI: 0.97-1.06, P = 0.51). In terms of dietary acid load based on potential renal acid load (PRAL) method, no significant non-linear association was seen with hypertension (P = 0.52). However, in linear dose-response analysis, a-20 unit increase in PRAL values was associated with 3% increased risk of hypertension (combined effect size: 1.03, 95% CI: 1.00-1.06, P = 0.03).

Conclusion: We found a significant positive association between dietary acid load and hypertension. Further studies, particularly those with prospective nature, are needed to confirm our findings.

Keywords: Acid-base equilibrium; Cardiovascular disease; Diet; Hypertension.