Effect of barberry (Berberis vulgaris) consumption on blood pressure, plasma lipids, and inflammation in patients with hypertension and other cardiovascular risk factors: study protocol for a randomized clinical trial

BACKGROUND: Cardiovascular diseases (CVDs) remain the leading causes of morbidity and mortality in the world. Hypertension is an important and prevalent cardiovascular risk factor. The present study will be conducted to investigate the effect of barberry as a cardio-protective fruit on the blood pressure in patients with hypertension and other CVD risk factors. Furthermore, plasma concentrations of lipids and inflammatory biomarkers will be evaluated. METHODS/DESIGN: This is an 8-week, prospective, single-blinded, parallel assigned, randomized controlled clinical trial (RCT) in which eligible men and women with hypertension and other cardiovascular risk factors will be randomized to either placebo powder (PP; containing 9 g maltodextrin, 1 g citric acid, 1 g milled sucrose and edible red color (n = 37)) or barberry powder (BP; containing 10 g milled dried barberry and 1 g of milled sucrose (n = 37)) groups. At baseline and after 8 weeks of intervention, plasma lipids and inflammatory markers, 24-h urinary nitrite/nitrate and sodium excretion, and 24-h ambulatory blood pressure monitoring (ABPM) will be measured. Anthropometric measures and dietary assessment will be performed as well. Data analysis will be done using SPSS version-21 software. DISCUSSION: The interest in natural and functional food products has increased globally. This RCT will add to the growing literature for the potential antihypertensive, lipid-lowering, and anti-inflammatory effects of barberry in humans. TRIAL REGISTRATION: ClinicalTrials.gov (NCT number) NCT04084847. Registered on 10 December 2019.