Corn Silk Tea for Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Shihua Shi,Siming Li,Weihao Li,Hao Xu

doi:10.1155/2019/2915498

Abstract

Corn silk, a traditional Chinese medicine, has been found to exert an antihypertensive effect in clinical practice and trials. However, systematic review of current evidence on this topic was not available. Thus, this study aims to assess safety and efficacy of corn silk tea (CST) in improving clinical outcomes in patients with hypertension. A systematic literature search was conducted through popular electronic databases up to October 2018. Randomized controlled trials (RCTs) comparing CST plus conventional antihypertensive drugs with conventional antihypertensive drugs alone were included. The main outcome was total blood pressure lowering efficacy. The risk of bias assessment according to the Cochrane Handbook was used to evaluate the methodological quality of the included trials. Review Manager 5.3 software was used for data analyses. Five RCTs involving 567 participants were included. Due to the poor quality of methodologies of most trials, limited evidence showed that CST plus antihypertensive drugs might be more effective in lowering blood pressure compared with antihypertensive drugs alone (RR = 1.27; 95% CI: 1.17 to 1.38, P<0.00001; heterogeneity: P = 0.51, I2 = 0%, fixed‐effect model). However, there is no evidence that CST plus conventional antihypertensive drugs has less adverse events than conventional antihypertensive drugs.

Highlights

High blood pressure (BP), as one of the most common diseases in the world [1], has been recognized as a major risk factor for cardiovascular and cerebrovascular diseases, leading to major health complications such as heart attack, strokes, and renal dysfunction [2–6]
We found one study evaluated the effectiveness of corn silk tea (CST) plus antihypertensive drugs on edema [21] and HCY [23]
Considering all above, we conducted this systematic review and meta-analysis of randomized clinical trials (RCTs) to clarify the clinical efficacy of CST plus conventional antihypertensive drugs on BP, where the main outcome was total blood pressure lowering efficacy

Summary

Introduction

High blood pressure (BP), as one of the most common diseases in the world [1], has been recognized as a major risk factor for cardiovascular and cerebrovascular diseases, leading to major health complications such as heart attack, strokes, and renal dysfunction [2–6]. Chinese and Native Americans used corn silk tea (CST) to lower BP for centuries, but there is a lack of reliable evidence of efficacy regarding CST treatment for hypertension all along. Corn silk (CS), as a traditional Chinese classical herb, was first recorded in the medical classic Materia Medica of South Yunnan by the Chinese physician Lan Mao (1397–1470) during the Ming dynasty of China. CS is considered an important medicinal plant, with the function of inducing diuresis and excreting dampness, alleviating syndrome of internal stagnation of fluid-dampness according to traditional Chinese medicine (TCM) theory [17]. CST has been claimed to have many benefits to human health such as decreasing inflammation, reducing edema, improving obesity, and lowering BP [16–20]. Several studies on CST and its health benefits on hypertension have been published [21–25] and the current evidence on its safety and efficacy has not been summarized. We conducted a systematic review and metaanalysis of randomized clinical trials (RCTs) to clarify the clinical efficacy of CST on BP

Objectives

Results

Discussion

Conclusion