Table 1 Characteristics of included studies

From: Effects of cocoa products/dark chocolate on serum lipids: a meta-analysis

Study Intervention Control Flavanol intake (active arm) Flavanol intake (control) Design Jadad score—quality ranking (0–5) Duration Population characteristics Number of subjects Age range (years) Location
Almoosawi et al. (2010) 20 g dark chocolate 20 g dark chocolate 1000 mg polyphenol 500 mg polyphenol Randomized crossover 2 2 weeks Healthy overweight and obese 14 21–50 UK
Balzer et al. (2008) Cocoa drink Placebo 963 mg flavanol 75 mg flavanol Randomized parallel group 5 30 days Medicated diabetic patients 41 50–80 Germany
Muniyappa et al. (2008) 31 g cocoa drink Placebo 900 mg flavanol 28 mg flavanol Randomized placebo-controlled crossover 4 2 weeks Mild-to-moderate hypertensive without medication 20 51±1.5 Bethesda, MD, USA
Crews et al. (2008) 37 g dark chocolate bar and cocoa beverage Placebo 754.71 mg proanthocyanin 0.20 mg/g proanthocyanin of chocolate bar; 40.87 mg/g of cocoa beverage Randomized placebo-controlled parallel group 4 6 weeks Healthy older adults 90 60 VA, USA
Davison et al. (2008) Cocoa mix Placebo 902 mg flavanol 36 mg flavanol Randomized placebo-controlled parallel group 4 12 weeks Overweight and obese 49 18–65 Australia
Grassi et al. (2005a, 2005b) 100 g dark chocolate 90 g white chocolate 88 mg flavanol 0 mg flavanol Randomized crossover 1 15 days Grade I essential hypertension 20 25–60 Italy
Fraga et al. (2005) 105 g milk chocolate Cocoa butter 168 mg flavanol 5 mg flavanol Randomized crossover 1 14 days Healthy males 27 18–20 Argentina
Grassi et al. (2005a, 2005b) 100 g dark chocolate 90 g white chocolate 88 mg flavanol 0 mg flavanol Randomized crossover 2 15 days Healthy 15 33.9±7.6 Italy
Engler et al. (2004) 46 g dark chocolate 46 g low-flavanol dark chocolate 213 mg procyanidins Trace Randomized, placebo-controlled parallel group 4 2 weeks Healthy 21 21–55 CA, USA
Wan et al. (2001) Average American diet supplemented with 16 g dark chocolate and 22 g cocoa powder Average American diet controlled for fiber, caffeine and theobromine 466 mg procyanidins Trace Randomized crossover 1 4 weeks Healthy 23 21–62 PA, USA