Effect of Cocoa and Tea Intake on Blood Pressure

Abstract

Background: Epidemiological evidence suggests blood pressure-lowering effects of cocoa and tea. We undertook a meta-analysis of randomized controlled trials to determine changes in systolic and diastolic blood pressure due to the intake of cocoa products or black and green tea.Methods: MEDLINE, EMBASE, SCOPUS, Science Citation Index, and the Cochrane Controlled Trials Register were searched from 1966 until October 2006 for studies in parallel group or crossover design involving 10 or more adults in whom blood pressure was assessed before and after receiving cocoa products or black or green tea for at least 7 days.Results: Five randomized controlled studies of cocoa administration involving a total of 173 subjects with a median duration of 2 weeks were included. After the cocoa

Dose-related effects of flavanol-rich cocoa on blood pressure

“…Despite the similarity of this protocol to that by which Grassi et al [4] showed BP reductions with chocolate, and despite providing almost double the daily dose of CF, there was no change in BP although there was some improvement in endothelial function. The lack of BP change in three of these studies and the relatively small change in the other following chronic consumption of large doses of CF are inconsistent with the results seen in the meta-analysis [6] and subsequent study [9] with flavanol rich chocolate consumption. These findings suggest that the dose of CF alone does not determine the change in BP, however a number of differences in the design of these studies makes direct comparisons difficult.…”

“…Several intervention studies have reported beneficial effects of consuming cocoa containing products on blood pressure (BP) [1][2][3][4][5] and a recent meta-analysis confirmed this effect by demonstrating that the consumption of cocoa-rich foods for seven or more days has the capacity to lower resting BP in normotensive and mildly hypertensive adults [6]. This effect of cocoa products has been widely attributed to its content of flavanols and procyanidins (oligomeric and polymeric flavanols), which for the purpose of this paper will be included in the term "cocoa flavanols" (CF) [7,8].…”

“…The recent meta-analysis [6] included five studies which compared the antihypertensive effects of CF-rich chocolate with chocolate containing few or no CF. The amount of chocolate consumed daily ranged from 46 to 105g and provided intakes of CF ranging from 246 to 500 mg/day.…”

The Effect of Dietary Supplementation of Green Tea Catechins on Cardiovascular Disease Risk Markers in Humans: A Systematic Review of Clinical Trials

“…The authors suggested that a reduction in the formation of reactive oxygen species in the vasculature and an enhanced endothelium relaxation of the aorta in these rats could be the cause of the hypotensive effects of the GTCs. A previous meta-analysis by Taubert et al [46] indicated that green and black tea had no significant effect on BP, whilst another by Liu et al [14] determined that GT could result in significant reductions of SBP and DBP. However, Taubert et al [46] 2007 findings were less conclusive, with a lower total subject pool (n = 173) for a meta-analysis and the average study duration was also short (two weeks).…”

Chocolate consumption and its relation to risk of type 2 diabetes mellitus

“…[1][2][3][4][5] Few randomized controlled clinical trials (RCT) have examined mechanisms by which chocolate in cocoa and flaven-3-ols potentially reduce CVD risk. [6][7][8][9][10] However, the predominant focus of these studies has been blood pressure effects and many of these studies examined its effects on systolic and diastolic blood pressure, LDL and HDL cholesterol. In addition, some of these RCT's reported a reciprocal relation between insulin resistance and chocolate consumption.…”