Table 1.
Studies carried out with cocoa flavanols (CF) in a population averaging under 25 years and with neurological or cognitive outcomes.
| Reference | Participants (Years Old) |
Type of Study | Flavanol Amount | Control Group | Time * | Outcomes | Results |
|---|---|---|---|---|---|---|---|
| [33] | 16 (female only) 18–30 | acute/chronic (5 days) | 172 mg CF for 5 days | 13 mg CF | 90 min | blood oxygenation level-dependent by fMRI | blood oxygenation in active brain regions fMRI |
| 4 24–31 |
acute | 516 mg CF | 39 mg | before, 2, 4& 6 h | cerebral blood flow increased 60% at 2 h after ingestion | ||
| [39] | 30 (17 female) 21.9 ± 0.61 |
acute | 520 mg & 994 mg of CF |
46 mg | 90 min | cognitive demand battery | improvement in serial 3 subtraction for all time point at 520 mg but not 994 mg and the same for fatigue improvement. |
| [40] | 30 (22 female) 18–25 | acute | 773 mg CF (222 mg theobromine y 35 mg caffeine) | Trace amounts | 2 h | visual contrast sensitivity and memory tasks | visual contrast sensitivity and integration time threshold, no effect on memory tasks |
| [37] | 18 (11 female) 10.55 ± 1.45 | chronic (10.11 ± 3.4 days) | 680 mg CF (30 g cocoa) | no flavanol for 15 days. | 4 h | Inflammation markers and short memory tests | decrease plasma endothelin1 and inflammatory mediators. In total, 83% of children showed a marginally significant improvement in one or both short memory tasks |
| [38] | 40 (27 female) 24.13 ± 4.47 | acute/chronic (28 days) | 250 mg CF (Tablet with 3 g cocoa) | placebo tablet | 2 h | subtraction, rapid visual processing, and a mental fatigue scale | improved self-reported mental fatigue and performance on the Serial Sevens task |
| [35] | 32 (16 female) 25.31 ± 3.60 | acute | 520 mg CF | 88.5 mg CF | 90 min | cognitive functions in sleep deprivation conditions | working memory accuracy is higher only in female after high flavanol chocolate consumption in sleep deprivation conditions than after low flavanol in the same conditions |
| [34] | 10 (0 female) 22.6 ± 0.3 | acute | 563 mg CF | 38 mg CF (Energy matched beverage) | 70 min | executive function and memory function (Stroop task, face-name matching) | CF could enhance exercise-induced improvement in executive function, but not in memory function |
| [41] | 20 (ND females) 23.2 ± 4.3 | acute | 530 mg CF | Capsules matched for theobromine and caffeine | 2 h | cognition battery and hemodynamic changes and neuronal activity | CF intake improved neurovascular coupling, but did not affect neuronal activity and cognitive performance in both normoxia and hypoxia |
| [42] | 48 (24 female) 22.15 ± 0.01 | acute | 747 mg and 37 4 mg CF | alkalinized cocoa | 2 h | cognition and visual functions | CF does not influence temporal attention, but does decrease reaction time in visual search with medium effect size and without losing accuracy |
| [36] | 20 (6 female) 20–31 | chronic (30 days) | 24 g/day dark chocolate | White chocolate | 20 h | cognitive function (Stroop and digital cancellation test). Prefrontal CBF | Increased Plasma Nerve Growth Factor, enhancing cognitive function performance |
| [43] | 98 (57 female) 20.7 ± 0.18 | acute | 35 g dark chocolate | White chocolate | 2 h | verbal episodic memory | dark chocolate consumption can benefit verbal episodic memory |
* Time for outcome assessment.