Cocoa flavanols and caffeine for attention and memory
What it found
In 48 young adults, drinks with cocoa flavanols, caffeine, or both did not change accuracy or speed on tests of attention and working memory.
The authors say the tested amounts had no measurable effect on these specific mental tasks.
What they found
Studies in people
Temporal attention
The drinks did not change accuracy or reaction times on the rapid serial visual presentation task. The expected attentional blink pattern appeared, but neither cocoa flavanols, caffeine, nor both together altered performance.
Spatial attention
On the visual search task, accuracy and reaction times were not significantly different between the placebo and any of the active drinks. The number of distractors affected performance as expected, but the drinks did not.
Working memory
In the delayed recall task, the number of items to remember changed accuracy, but the drinks did not affect how well or how quickly participants responded.
Caffeine and reaction time
There was a marginal trend toward faster responses on the temporal attention task after caffeine alone and after caffeine plus flavanols, but the differences were not significant after correcting for multiple comparisons.
What the authors conclude
“We conclude that, even when jointly ingested, neither the tested amount of cocoa flavanols nor caffeine have acute effects that are robustly measurable on cognitive tasks that target attention and working memory specifically.”
Also in their conclusions
- They conclude that even when jointly ingested, neither the tested amount of cocoa flavanols nor caffeine have acute effects that are robustly measurable on cognitive tasks that target attention and working memory specifically.
- They suggest that flavanols and caffeine might mainly affect early visual functions or other cognitive functions like executive functions, which could explain previous positive findings.
How it was done
Cocoa flavanols and caffeine might quickly improve thinking, especially when taken together. Past studies used mixed tasks, so it was unclear which mental functions were affected.
Forty-eight university students took part in four sessions. In each session they drank a placebo, a cocoa flavanol drink (415 mg), a caffeine drink (215 mg), or a drink with both. After 90 minutes they did three computer tasks testing attention over time, attention in space, and working memory.
What it can’t tell you
- This trial tested only healthy young university students, so the results may not apply to other groups such as older adults or people who are tired or sleep-deprived.
- The study did not control for participants' usual intake of flavanols and caffeine, so it cannot rule out that withdrawal effects influenced the results.
- The trial only looked at three specific cognitive tasks; it cannot show whether these substances affect other mental functions like executive control or inhibition.
Who paid
- Conflicts
- Declarations. Conflicts of interest: The authors declare no conflicts of interest.
- Authors work at
- University of Groningen, The Netherlands; New York University Abu Dhabi, United Arab Emirates
The paper
- Title
- Concurrent consumption of cocoa flavanols and caffeine does not acutely modulate working memory and attention
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Akyürek EG, Altınok A, Karabay A (2024). Concurrent consumption of cocoa flavanols and caffeine does not acutely modulate working memory and attention. European journal of nutrition. doi:10.1007/s00394-024-03514-8Free full textPubMed 39607519DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error