Ginseng for Reducing the Blood Pressure in Patients with Hypertension: A Systematic Review and Meta-Analysis

Ginseng is one of the most-widely used herbal remedies. This systematic review evaluates the current evidence for its use in the reducing blood pressure (BP) in patients with hypertension. Systematic searches of 12 electronic databases were conducted without language restrictions. All randomized clinical trials (RCTs) of ginseng as a treatment for hypertension were candidates for inclusion. Methodological quality was assessed using the Cochrane risk of bias. Five RCTs met the inclusion criteria. The risk of bias was low in most of the trials. Four of the included RCTs compared the effectiveness of ginseng to placebo. The meta-analysis of these data failed to show a statistically significant acute effect on systolic BP (SBP) or diastolic BP (DBP). However, subgroup analyses showed beneficial effects of Korean red ginseng (KRG) on both SBP (n=54, mean difference [MD], -6.52; 95% confidence interval [CI], -9.99 to -3.04; p=0.0002) and DBP (n=54, MD, -5.21; 95% CI, -7.90 to -2.51; p=0.0001). Two RCTs tested the long-term effects of ginseng for BP for 24hours. One of these trials failed to show any benefits of KRG compared to no treatment, and the other failed to show superior effects of North American ginseng compared to placebo. Adverse events with ginseng were none in one trial or not assessed. Collectively, these RCTs provide limited evidence for the acute effectiveness of KRG in the treatment of high BP. The total number of RCTs included in the analysis and the total sample size were insufficient to draw definitive conclusions. More rigorous studies are warranted.