Blood pressure lowering effects of alpha-lipoic acid supplementation: a meta-analysis of randomized controlled trials

Background: The aim of the present meta-analysis was to detect the effect of a-lipoic acid (ALA) supplementation on systolic and diastolic blood pressure (BP). Material and methods: The related records were selected from several electronic databases from the earliest date 1980 until October 2019. The heterogeneities were assessed by I 2 test (I 2 < 50%) and X 2 test on Cochrane’s Q statistic. Standardized mean difference (SMD) and their 95% confidence intervals (CIs) were considered for net change in systolic blood pressure (SBP) and diastolic blood pressure (DBP). Subgroup analyses were also conducted by baseline BP, health status, doses of supplementation, study duration and supplement utilization. Results: As a result, a total of 10 studies with 612 subjects were included in the final analysis. Alpha-lipoic acid supplementation significantly reduced SBP (SMD = –0.50, 95% CI: –0.84, –0.16, p = 0.004) and DBP (SMD = –0.40, 95% CI: –0.71, –0.09, p = 0.01), compared to the controls, with the reduction of 6.1 mm Hg and 3.6 mm Hg of the mean SBP and DBP, respectively. Heterogeneities were explored in both SBP and DBP. Moreover, a statistically significant reduction in BP was detected in elevated BP and hypertensive patients as compared with the normotensive subjects. Conclusion: ALA supplementation could be considered as a BP-lowering agent, especially in subjects with higher blood pressure.