Evidence · Replicated

What the research found

In the cited research, the C allele at rs4410790 was associated with slightly more cups of coffee a day among coffee drinkers.

TT: Fewer cups
CT: Middle
CC: More cups

Slight effect

What the study found

In the study, the average average caffeine intake a day, mostly from coffee, by genotype:

TTNo copy: 268 mg
CTOne copy: 295 mg
CCTwo copies: 315 mg

Women's Genome Health Study, US women of European descent · 22,658 people · Supplementary Table S3 (its own file, pgen.1002033.s005.docx: 'Mean caffeine intake (mg/d) by rs4410790 genotype'), WGHS row; the C/C minus T/T difference is also quoted in the Discussion

Evidence: Genome-wide meta-analysis with independent replication
Who was studied: European ancestry, US cohorts (ARIC, PLCO, NHS, HPFS and WGHS)

1000 Genomes Project

How common each genotype is

How common each genotype is in the 1000 Genomes Project, by region
Region	TTFewer cups	CTMiddle	CCMore cups
All regions2,504 people	30%	47%	23%
Africa661 people	31%	50%	19%
The Americas347 people	43%	39%	18%
East Asia504 people	35%	47%	18%
Europe503 people	16%	46%	39%
South Asia489 people	27%	52%	21%

Among the 2,504 people of the 1000 Genomes Project, in five world regions. These percentages describe groups of people, never anyone’s chance of having a trait.

Ancient genomes

Through time

How often the studied letter was read in ancient people, era by era, in the region chosen.

Region

Through time: Europe
Before farmingbefore 6500 BC	88%28 of 32 copies read
First farmers6500 to 3000 BC	66%239 of 364 copies read
Bronze Age3000 to 1200 BC	64%160 of 249 copies read
Iron Age and Antiquity1200 BC to AD 600	59%228 of 389 copies read
Middle AgesAD 600 to 1500	67%228 of 341 copies read
Today1000 Genomes	62%619 of 1,006 copies

Neanderthal and Denisovan genomes

Altai Neanderthal: No copies
Vindija Neanderthal: No copies
Chagyrskaya Neanderthal: No copies
Denisovan: No copies

Neanderthals and Denisovans carried the other letter, so this letter is younger than our split with them.

For most ancient people only one of their two copies can be read, so these counts are copies read, not people. Close relatives, repeated samples and samples the archive marks as unreliable are left out. Damage in old DNA can fake this letter, so it is counted only from samples treated to remove that damage and from high-quality genomes. Ancient genomes from the Allen Ancient DNA Resource (AADR v66): 15,136 people.

rs4410790

The marker

Gene or region: AHR
Marker: rs4410790
Location: Chromosome 7 · GRCh37 17,284,577 · GRCh38 17,244,953
Letters studied: C and T, with C as the studied allele

A DNA Traits report reads this marker in your raw DNA file and shows which of the three genotypes is yours, with how common it is. It counts the copies of the studied allele; it does not measure the trait itself.

Marker: AHR · rs4410790
Location: Chromosome 7 · GRCh37 17,284,577 · GRCh38 17,244,953
Studied allele: C
Published statistic: Cube-root caffeine intake: beta -0.15 (SE 0.02) per T, EAF 0.38, P 2.4e-19, n 36,013 (Table 2); never smokers -0.19, P 1.8e-14 (Table 3); crude weighted C/C minus T/T difference 44.4 mg a day across eight studies (Table S3, pgen.1002033.s005.docx). Coffee cups a day per T: stage 1 -0.14 (0.01), P 1.48e-57; stage 2 European -0.05 (0.01), P 1.66e-4; all stages -0.10 (0.01), n 116,674 (Cornelis 2015 Table 1). Zhong 2019 Table 2: +3.94% coffee per C, joint P 5.59e-141. UK Biobank: beta -0.0569 SD per T on inverse-rank-normalised cups of coffee a day, P 1.1e-150 (Cole 2020) (Supplementary Table S3 (its own file, pgen.1002033.s005.docx: 'Mean caffeine intake (mg/d) by rs4410790 genotype'), WGHS row; the C/C minus T/T difference is also quoted in the Discussion)
1000 Genomes Project phase 3, people with 0, 1 and 2 copies: All regions 742 / 1185 / 577 · Africa 205 / 330 / 126 · The Americas 150 / 135 / 62 · East Asia 177 / 237 / 90 · Europe 79 / 229 / 195 · South Asia 131 / 254 / 104

See this card in the sample report

Limits

What it cannot tell you

The figure shown is total caffeine from all sources in one cohort of US women; coffee supplied most of it.

Genome-wide meta-analysis identifies regions on 7p21 (AHR) and 15q24 (CYP1A2) as determinants of habitual caffeine consumption (Cornelis et al., 2011)

The same topic

More in Nutrition & metabolism

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