Evidence map›Paper›PMID 32356023›Full record

ArticleEuropean journal of applied physiology2020

The effect of caffeine on cognitive performance is influenced by CYP1A2 but not ADORA2A genotype, yet neither genotype affects exercise performance in healthy adults.

Alexander T Carswell, Kevin Howland, Borja Martinez-Gonzalez, Pauline Baron, Glen Davison

Abstract read
In one paragraph

Article in European journal of applied physiology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 31 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
31citing papers in PubMed, 3 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

31 citing papers in PubMed, 3 syntheses or guidelines pooled it.

  1. Pooled it
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  8. Influence of the CYP1A2 c.European journal of nutrition · 2024
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  9. Effect ofNutrients · 2024
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  14. Habitual caffeine intake, genetics and cognitive performance.Journal of psychopharmacology (Oxford, England) · 2025
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Alexander T CarswellEndurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham, Kent, UK.ORCID http://orcid.org/0000-0002-7922-5549
Kevin HowlandSchool of Biosciences, University of Kent, Canterbury, Kent, UK.ORCID http://orcid.org/0000-0003-4370-0974
Borja Martinez-GonzalezEndurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham, Kent, UK.ORCID http://orcid.org/0000-0002-2015-8783
Pauline BaronEndurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham, Kent, UK.
Glen DavisonEndurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham, Kent, UK. g.davison@kent.ac.uk.ORCID http://orcid.org/0000-0003-4340-0074

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeTo determine the influence of two commonly occurring genetic polymorphisms on exercise, cognitive performance, and caffeine metabolism, after caffeine ingestion.

methodsEighteen adults received caffeine or placebo (3 mg kg

resultsCaffeine enhanced exercise performance (P < 0.001), but effects were not different between participants with ADORA2A 'high' (n = 11) vs. 'low' (n = 7) sensitivity genotype (+ 6.4 ± 5.8 vs. + 8.2 ± 6.8%), or CYP1A2 'fast' (n = 10) vs. 'slow' (n = 8) metabolism genotype (+ 7.2 ± 5.9 vs. + 7.0 ± 6.7%, P > 0.05). Caffeine enhanced PVT performance (P < 0.01). The effect of caffeine was greater for CYP1A2 'fast' vs. 'slow' metabolisers for reaction time during exercise (- 18 ± 9 vs. - 1.0 ± 11 ms); fastest 10% reaction time at rest (- 18 ± 11 vs. - 3 ± 15 ms) and lapses at rest (- 3.8 ± 2.7 vs. + 0.4 ± 0.9) (P < 0.05). There were no PVT differences between ADORA2A genotypes (P > 0.05). Serum caffeine and paraxanthine responses were not different between genotypes (P > 0.05).

conclusionCaffeine enhanced CYP1A2 'fast' metabolisers' cognitive performance more than 'slow' metabolisers. No other between-genotype differences emerged for the effect of caffeine on exercise or cognitive performance, or metabolism.

Indexed as

GenotypeAdultCaffeineCytochrome P-450 CYP1A2ExerciseFemaleHumansMalePerformance-Enhancing SubstancesReceptor, Adenosine A2AYoung AdultADORA2A protein, humanCaffeineCYP1A2 protein, humanCytochrome P-450 CYP1A2Performance-Enhancing SubstancesReceptor, Adenosine A2ACaffeineCognitive performanceEndurance exerciseErgogenicGeneticsPolymorphism

Identifiers

PMID32356023
PMCPMC7295849

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.