Table 1.
Characteristics of trials included in the meta-analysis
| Trial; Location | Study design; treatment/control groups | Dosage; duration | Active ingredients per daily dosage | Mean age; mean BMI | N treatment/control | Mean SBP (SD) in mmHg at start/end of treatment versus control | Mean DBP (SD) in mmHg at start/end of treatment versus control |
|---|---|---|---|---|---|---|---|
| Taubert et al. [10]; Germany | Crossovera,b | 100 g/d; | 500 mg polyphenols | 59.5 yr; | 13/13 | Cocoa: 153.4 (4.4)/148.6 (2.4); | Cocoa: 84.5 (4.6)/82.9 (4.6); |
| Dark/white chocolate | 14 d | 24.1 | Control: 153.6 (4.4)/154.0 (3.6) | Control: 84.2 (4.2)/84.5 (4.3) | |||
| Murphy et al. [15]; Australia | Parallel; | 6 tablets/d | 234 mg flavanols; | 43.5 yr; | 13/15 | Cocoa: 118 (13)/120 (12); | Cocoa: 78 (12)/77 (10); |
| High/low flavanol cocoa tablets | 28 d | Control: 6.4 mg | 26.0 | Control: 116 (9)/119 (8) | Control: 76 (8)/76 (7) | ||
| Engler [11]; USA | Parallel; | 46 g/d; | 213 mg procyanidins | 32.1 yr; | 11/10 | Cocoa: 121 (17.9)/120 (13.3) | Cocoa: 68.1 (8.3)/69 (6.6) |
| High/low flavanoid chocolate | 14 d | 22.6 | Control: 112.8 (8.9)/110 (6.3) | Control: 66.1 (5.4)/66 (6.3) | |||
| Fraga et al. [12]; USA | Crossovera; | 105 g/d; | 168 mg flavanols | 18.0 yr; | 27/28 | Cocoa: 123 (11.2)/117 (7.5) | Cocoa: 72 (7.5)/67 (7.5) |
| Dark/white chocolate | 14 d | 24.1 | Control: 123 (11.2)/121 (7.5) | Control: 71 (7.5)/70 (7.5) | |||
| Grassi (normotensive arm) [13]; Italy | Crossovera,b; | 100 g/d; | 500 mg polyphenols | 33.9 yr; | 15/15 | Cocoa: 112.9 (8.5)/105.9 (6.6) | Cocoa: 74.0 (5.7)/69.8 (4.5) |
| Dark/white chocolate | 15 d | 22.6 | Control: 113.2 (7.9)/112.7 (7.6) | Control: 73.8 (5.5)/73.5 (5.3) | |||
| Grassi et al. (hypertensive arm [13]; Italy | Crossovera,b; | 100 g/d; | 500 mg polyphenols | 43.7 yr; | 20/20 | Cocoa: 141.3 (4.8)/129.3 (5.7); | Cocoa: 92.4 (3.8)/84.6 (5.6); |
| Dark/white chocolate | 15 d | 25.4 | Control: 141.1 (5.4)/140.4 (4.6) | Control: 91.8 (4.7)/91.2 (4.7) | |||
| Taubert et al. [16]; Germany | Parallela; | 6.3 g/d; | 30 mg polyphenols | 63.6 yr; | 22/22 | Cocoa: 147.7 (7.1)/144.8 (ng); | Cocoa: 86.4 (4.1)/84.5 (ng); |
| Dark/white chocolate | 126 d (18 wk) | 24.0 | Control: 147.5 (8.0)/147.6 (ng) | Control: 86.7 (3.8)/86.7 (n.g.) | |||
| Crews et al. [17]; USA | Parallela; | 37 g/d choc + 11 g/d drink; | 754 mg proanthocyanins; | 68.8 yr; | 45/45 | Cocoa: 126.8 (14.3)/123.3 (12.3); | Cocoa: 74.2 (8.2)/73.7 (7.5); |
| Dark chocolate + cocoa drink/low flavanol chocolate + drink | 42 d (6 wk) | Control: 41.1 mg | 25.3 | Control: 128.6 (14.3)/125.5 (12.7) | Control: 75.0 (8.0)/74.4 (7.7) | ||
| Grassi et al. [18]; Italy | Crossovera,b; | 100 g/d; | 1008 mg phenols | 44.8 yr; | 19/19 | Cocoa: 141.1 (3.4)/137.3 (4.0); | Cocoa: 91.2 (4.2)/87.3 (4.6); |
| Dark/white chocolate | 15 d | 26.5 | Control: 140.9 (3.4)/140.8 (3.5) | Control: 91.1 (3.7)/90.9 (3.5) | |||
| Muniyappa et al. [20]; USA | Crossovera,b; | 31 g/d cocoa; | 900 mg polyphenols; | 51.0 yr; | 20/20 | Cocoa: 141 (13)/139 (9); | Cocoa: 91 (13) 88 (9); |
| High flavanol cocoa/low flavanol drink | 14 d | Control: 28 mg | 33.2 | Control: 141 (13)/140 (9) | Control: 91 (13)/87 (9) | ||
| Davison et al. (nonexercise arm) [21]; Australia | Parallel; | 300 ml drink mix/d; | 902 mg flavanols; | 44.9 yr; | 12/11 | Cocoa: 124 (10.4)/122.1 (ng); | Cocoa: 76 (6.2)/74.2 (ng); |
| High flavanol cocoa/low flavanol drink | 84 d (12 wk); | Control: 36 mg | 33.6 | Control: 124 (5.97)/128.2 (ng) | Control: 77 (5.0)/79.8 (ng) | ||
| Davison (exercise arm)[21]; Australia | Parallel; | 300 ml drink mix/d; | 902 mg flavanols; | 45.4 yr; | 13/13 | Cocoa: 126 (10.4)/127.1 (ng); | Cocoa: 78 (8.7)/77.5 (ng); |
| High flavanol cocoa/low flavanol drink | 84 d (12 wk) | Control: 36 mg | 33.4 | Control: 121 (13.0)/120.5 (ng) | Control: 74 (5.8)/73.8 (ng) | ||
| Shiina et al. [22]; Japan | Parallela; | 45 g/d | 550 mg polyphenols | 29.8 yr; | 20/19 | Cocoa: 116.4 (12.7)/121.0 (12.7); | Cocoa: 64.7 (11.7)/71.3 (10.8); |
| Dark/white chocolate | 14 d | 22.6 | Control: 121.6 (14.9)/125.6 (11.4) | Control: 72.2 (13.8)/77.4 (11.6) | |||
| Ried et al. (phase 1) [23]; Australia | Parallel; | 50 g/d; | 750 mg polyphenols | 53.1 yr; | 11/10 | Cocoa: 135.0 (12.5)/133.1 (11.7)c; | Cocoa: 83.6 (10.6)/84.5 (11.6); |
| Dark chocolate/placebo pill | 56 d (8 wk) | 26.6 | Control: 135.7 (12.4)/130.8 (18.3)c | Control: 77.8 (8.6)/77.3 (10.0) | |||
| Monagas et al. [24]; Spain | Crossover; | 40g/d + 250 skim milk; control: 500 ml skim milk | 495 mg polyphenols | 69.7 yr; | 42/42 | Cocoa: 138 (26)/138 (16); | Cocoa: 84 (13)/82 (13); |
| Cocoa powder in milk/milk only | 28 d | 27.6 | Control: 138 (26)/135 (24) | Control: 84 (13)/81 (13) |
a7-day cocoa/flavanol-free run-in period.
b7-day washout period before crossover.
cMedian.
BMI, body mass index; DBP, diastolic blood pressure; g/d, grams per day; mg; milligrams; ml, millilitre; N, number of participants; ng, not given; SBP, systolic blood pressure; SD, standard deviation; yr, years; wk, weeks