Table 1.
The effect of CF supplementation on exercise-induced oxidative stress
| Reference | Participants | Nutritional intervention | Supplementation period | Exercise stimulus | Measure(s) | Key outcome(s) |
|---|---|---|---|---|---|---|
| Allgrove et al. [42] |
20 healthy males Age 22 ± 4 years Mass 74.6 ± 8 kg V̇O2max 53.1 ± 7.0 ml·kg−1 Power output 300 ± 30 W |
CF: 80 g dark chocolate a day for 14 days, 197.4 mg CF per dose (EPI: 77.4 mg, CAT: 31.2 mg) CON: 56.8 g iso-CHO-fat control chocolate, 0 mg CF |
Each day for 14 days, with a half dose 2 h pre-exercise |
Cycling at 60% V̇O2max for 1.5 h, intensity raised to 90% every 10 min for 30 s 5 min post cycling there was a time to exhaustion trial at 90% V̇O2max |
(i) F2-isoprostanes (ii) Oxidised LDLs (iii) Plasma uric acid (iv) TEAC (v) Plasma vitamin C |
(i) significantly ↓ in CF group (ii) significantly ↓ across each time point in CF group (iii) ↑ post-exercise in both treatments (iv) ↔ between groups (v) ↔ between groups |
| Davison et al. [47] |
14 healthy males Age 22 ± 1 years Mass 71.6 ± 1.6 kg V̇O2max 53.1 ± 1.9 ml·kg−1 min−1 Power output 300 ± 12 W |
CF: 100 g dark chocolate 246.8 mg CF (EPI: 96.8 mg, CAT: 39.1 mg) CON: isomacronutrient control, 0 mg CF None: water |
Acute dose 2 h pre-exercise | Cycling at ~ 60% V̇O2max for 2.5 h |
(i) F2-isoprostanes (ii) Plasma Vitamin C (iii) TEAC |
(i) ↓ CF group vs CON (ii) ↔ between groups (iii) ↑ pre-exercise CF vs CON |
| de Carvalho et al. [49] |
13 trained males Age 21 ± 2 years Stature 180 ± 0.05 cm Mass 87.02 ± 8.03 kg |
CF: CHO + protein cocoa beverage, 306 mg CF per beverage CON: cocoa based CHO + protein beverage, 0 mg CF |
7 days, beverage consumed twice daily | Five sets of 20 drop jumps from 0.6 m, 10 s between jumps and 2 min interset rest | Urinary F2-isoprostanes | ↔ between groups |
| Decroix et al. [43] |
12 well-trained males Age 30 ± 3 years Stature 177.9 ± 8.8 cm Mass 72.8 ± 7.8 kg V̇O2max 63.0 ± 3.5 ml·kg−1 min−1 |
CF: cocoa drink, 900 mg CF (EPI: 185 mg, CAT: 20 mg) CON: placebo, 15 mg CF (EPI: 0 mg, CAT: 0 mg) |
Acute dose 1.5 pre-exercise | Two 30 min time trials 60 min apart, performed at a ~ 75% peak power output |
(i) Uric acid (ii) MDA (iii) TEAC |
(i) ↑ in CF vs CON (ii) ↔ between group (iii) ↑ in CF vs CON |
| Decroix et al. [45] |
14 well-trained males Age 31 ± 3 years Stature 180 ± 5 cm Mass 73 ± 7 kg V̇O2max 62.9 ± 5.8 ml·kg−1 min−1 Peak Power Output 366 ± 45 W |
CF: Capsule, 530 mg CF (EPI: 100 mg, CAT: 21 mg) CON: 1,764 mg maltodextrin |
Consumed daily for six days and then a seventh on the day of testing |
20 min steady state cycling at 45% peak power output 20 min time trial beginning at 75% peak power output Completed in normoxic and hypoxic environments |
(i) TEAC (ii) Uric acid (iii) MDA |
(i) ↔ (ii) ↔ (iii) CF blunted ↑ in both N and H |
| Fraga et al. [41] |
28 trained males Age 18 ± 1 years Mass 74 ± 1 kg |
CF: 105 g chocolate confectionery, 168 mg CF (EPI + CAT: 39 mg) CON: 105 g cocoa butter chocolate, < 5 mg CF |
Sub-chronic, 14 day consumption | Soccer training sessions twice per week and one match per week |
(i) MDA (ii) Urate (iii) Oxo8dG (iv) TRAP (v) α-tocopherol (vi) lycopene vii) β-carotene (viii) coenzyme Q-10 |
(i) Post CF ↓ by 12% CON ↑ by 10% (ii) ↓ by 11% in CF (iii-viii) ↔ between groups |
| Morgan et al. [48] |
10 active males Age 23 ± 3 years Stature 184 ± 59 cm Mass 85.3 ± 12.0 kg Single leg 1RM 90.4 ± 19.0 kg |
CF: 330 ml cacao juice, 74 mg CF (EPI: 8 mg, CAT: 43 mg) CON: 330 ml CHO and flavour matched placebo, 0 mg CF |
10 days supplementation (7 days pre-exercise, 3 days post) | 10 sets of 10 single leg knee extensions at ~ 80% 1RM | Protein carbonylation | Protein carbonylation not elevated following exercise protocol |
| Taub et al. [50] |
17 sedentary (9 males 8 females) participants CF: Age 50 ± 3 Stature 168 ± 3 Mass 78.8 ± 5.6 V̇O2max 22.9 ± 1.9 ml·kg−1 min−1 CON: Age 50 ± 2 Stature 175 ± 5 Mass 92.2 ± 9.7 V̇O2max 24 ± 1.7 ml·kg−1 min−1 |
CF: 20 g dark chocolate, 175.2 mg CF (EPI: 26 mg, CAT: 4.6) CON: 20 g placebo chocolate |
Chronic (3 months daily intake) | Cycling exercise including V̇O2max |
(i) GSH:GSSG ratio (ii) Protein carbonylation |
(i) significant ↑ in CF group vs CON (ii) significant ↓ in CF group vs CON |
| Wiswedel et al. [44] |
20 untrained males Age ~ 20–25 |
CF: cocoa drink, 185 mg CF CON: cocoa drink 14 mg CF |
Acute, 2 h pre cycling exercise | Cycling at 75 W increasing to 150 W for 10 min |
(i) F2-isoprostanes (ii) MDA (iii) α-tocopherol (iv) ascorbate (v) TAC |
(i) CON small ↑ 2 and 4 h post-consumption, CF did not Significant difference CF vs CON 2 and 4 h post-intake following exercise (ii–v) ↔ between groups |
CF, cocoa flavanols; EPI, epicatechin; CAT, catechin; CON, control;CHO, carbohydrate; TEAC, Trolox equivalent antioxidant capacity; MDA, malonaldehyde; LDL, low density lipoprotein; Oxo8dG, 8-Oxo-2’-deoxyguanosine; 1RM, one rep max; GSH:GSSG, reduced glutathione: oxidised glutathione ratio; TAC, total antioxidant capacity; TRAP, total relative antioxidant potency; ↑, increase; ↓, decrease; ↔ , no significant effect/change