Table 2.
Summary of the studies examining the effects of acute administration of cocoa flavanols on cognitive performance.
| Reference | Participants | Flavanols amount | Cognitive measures | Principal findings |
|---|---|---|---|---|
| Scholey et al. (44) | 30 subjects (13 males, 17 females; 18–35 years) | Dairy based cocoa drinks containing 994, 520, and 46 mg flavanols (control) | Rapid Visual Information Processing Task, Serial Threes Subtraction, Serial Sevens Subtraction | Improvements in Serial Threes performance following 994 and 520 mg flavanols compared to 46 mg. Improved visual information processing performance after 994 mg flavanols |
| Field et al. (45) | 30 subjects (8 males, 22 females; 18–25 years) | Dark chocolate containing 773 mg flavanols and white chocolate (control) | Choice Reaction Time, Visual Spatial Working Memory Test | Improvements in spatial working memory performance and choice reaction time in the flavanol condition |
| Pase et al. (46) | 71 subjects (40–65 years; 34% males) | Chocolate drinks containing 500, 250, or 0 mg flavonoids (placebo) | Mood assessment, Cognitive Drug Research Battery measuring working memory, episodic memory, speed of memory and attention | No differences in cognitive performance between placebo and treatment groups |
| Massee et al. (47) | 40 subjects (18–40 years; 16% males) | Cocoa bars containing 250 or 0 mg flavanols (placebo) | Mental fatigue assessment, Serial Threes and Serial Sevens, Rapid Visual Information Processing Task | Improvements in serial sevens subtraction performance and self-reported mental fatigue in the flavanol group. No significant effect for cardiovascular measures |
| Decroix et al. (48) | 12 subjects (all males; mean age: 30 years) | Cocoa drinks containing 903 and 15 mg flavanols (placebo) | Stroop task | Increased cerebral blood oxygenation (NIRS) during the task with no significant behavioral effect |
| Grassi et al. (27, 28) | 32 subjects(16 males, 16 females; mean age: 25.3 years) | Chocolate bars containing 520 mg (flavanol-rich) and 88.5 mg flavanols (flavanol-poor) | Psychomotor Vigilance Task, 2-back task | Improvements in 2-back task accuracy after flavanol-rich treatment following a night of total sleep deprivation, in females. In the sleep condition, correlation between 2-back accuracy and FMD for the whole sample |
FMD, flow-mediated dilation; NIRS, near-infrared spectroscopy.