Table 2 Characteristics of included acute studies, including information on population studied and interventions used
|  | Study design (washout period) | Participants’ health | Number of participants | Age (yrs) | % female | Cocoa intervention type/dose | Control intervention type | Microcirculation studied |
|---|---|---|---|---|---|---|---|---|
(a) Bapir 2022 [56] | Crossover | Healthy | n = 11 | 51 ± 10 | 72.7% | 6 capsules- Total flavs: 1350mg Epicatechin: 255mg | 6 capsules containing 3.9 g brown sugar- Total flavs: 0mg | Cutaneous (hands/feet) |
T2DM | n = 11 | 59 ± 10 | 27.3% | |||||
(c) Neukam 2007 [45] | Crossover (14 days) | Healthy | n = 10 | 18–65 | 100% | Cocoa beverage (18 g cocoa powder in 100 ml water) Total flavs: 329mg Epicatechin: 61.1mg | Matched beverage (18 g cocoa powder in 100 ml water) Total flavs: 27mg Epicatechin: 6.6mg | Cutaneous |
(d) Kim 2020 [62] | Crossover (min 7days) | (d1) Healthy WEs | n = 7 | 22 ± 4 | 42.9% | Cocoa beverage (in 250 ml water)- Total flavs: 528mg Epicatechin: 47mg | Matched placebo beverage (in 250 ml water) Total flavs: 0mg | Cutaneous (forearm) |
(d2) Healthy BAs | n = 7 | 22 ± 4 | 42.9% | |||||
(e) Hammer 2015 [61] | Crossover (7 days) | PAD patients | n = 21 | 66.9 ± 7.41 | 28.6% | 50 g dark choc Total flavs: 780mg Epicatechin: 45mg | 50 g white choc Total flavs: 0mg | Cutaneous (forearm) |
(b) Heiss 2015 [72] | Parallel | (b1) Healthy young (18-30yrs) | n = 22 | 26 ± 4.69 | 0% | Cocoa beverage (7 g cocoa powder in ~ 500 ml water) Total flavs: 450mg Epicatechin: 64mg | Cocoa beverage (7 g matched powder in ~ 500 ml water) Total flavs: 0mg | Cutaneous/ muscle (forearm) |
(b2) Healthy elderly (50-80yrs) | n = 20 | 60 ± 8.94 | 0% | |||||
(f) Baynham 2021 [55] | Crossover (7 days) | Healthy (all White European) | n = 30 | 23 ± 4.3 | 0% | 8.3 g cocoa powder (dissolved in 300 ml Buxton water) Total flavs: 681.4mg Epicatechin: 150mg | 8.3 g matched cocoa powder (dissolved in 300 ml Buxton water) Total flavs: 4.1mg Epicatechin: <4mg | Skeletal muscle (forearm) |
(g) Santos 2023 [63] | Crossover (1 month) | Healthy | n = 12 | 25 ± 4 | 53.8% | 25 mg microencapsulated cocoa powder (dissolved in 250 ml water) Total flavs: 80mg | 7 g microencapsulated Ovaltine Total flavs: 9mg | Skeletal muscle (forearm) |
(h) Scuderi 2020 [64] | Crossover (72 h) | Healthy | n = 18 (36 eyes) | 26.3 ± 1.5 | 44.4% | 100 g dark chocolate Epicatechin: 447mg | 100 g white chocolate Total flavs: trace | Retinal |
(i) Siedlecki 2019 [65] | Crossover (7 days) | Healthy | n = 22 | 27.3 ± 11.1 | 59.1% | 20 g dark chocolate Total flavs: 400mg | 7.5 g milk chocolate Total flavs: 5mg | Retinal |
(j) Decroix 2018a [59] | Crossover (7 days) | Healthy | n = 20 | 23.2 ± 4.3 |  | 4 capsules (1765 mg cocoa extract) Total flavs: 530mg Epicatechin: 100mg | 4 matched capsules Total flavs: 0mg | Cerebral |
(k) Decroix 2016 [58] | Crossover (7days) | Trained males | n = 12 | 30 ± 3 | 0% | Cocoa powder dissolved in 300 ml semi-skimmed milk Total flavs: 903mg Epicatechin: 185mg | Matched placebo powder dissolved in 300 ml semi-skimmed milk Total flavs: 15mg Epicatechin 0mg | Cerebral |
(l) Gratton 2020 [60] | Crossover (2 weeks) | Healthy | n = 18 | 23.9 ± 7.3 | 0% | 8.3 g cocoa powder (dissolved in 300 ml Buxton water) Total flavs: 681.4mg Epicatechin: 150mg | 8.3 g matched cocoa powder (dissolved in 300 ml Buxton water) Total flavs: 4.1mg Epicatechin: <4mg | Cerebral |
(m) Bloomfield 2023 [57] | Crossover (2 weeks) | Healthy | n = 12 | 26.1 ± 6.2 | 41.7% | Encapsulated cocoa powder (15 mg/kg body weight) Mean total flavs: 1031mg Mean epicatechin: 145mg | Encapsulated placebo cocoa powder Mean total flavs: 0.82mg Mean epicatechin: n/a | Cerebral |