Coffee consumption

How much coffee people drink is partly genetic, tied to caffeine metabolism and sensitivity. This score estimates your inherited leaning toward higher or lower coffee intake.

What this coffee score reads

This is PGS001123, one of 813 trait scores generated by Tanigawa and colleagues in 2022 using snpnet, a sparse regression method, on UK Biobank data from 116,930 European-ancestry participants. It contains 48 variants.

Its largest weight is the AHR variant rs4410790, and the second is near CYP1A2. Those two genes are the caffeine metabolism machinery: CYP1A2 makes the enzyme that clears caffeine, and AHR controls how much of it you produce. This site reads them together as a caffeine metabolism result, which is the more interpretable version of what this score is picking up.

How well it predicts coffee drinking

The authors reported the score on its own, without covariates, which is unusually candid: its area under the curve was 0.517 to 0.525 across ancestry groups, against 0.5 for a coin flip, and it explained between 0.03% and 0.3% of the variation in coffee consumption.

In other words, this score is close to uninformative about whether a given person drinks coffee. The higher figures reported for it, around 0.60, come from models that also include age, sex and genetic ancestry components, and those covariates do the work.

Why the genetic signal here is real but small

The biology is genuine. People who clear caffeine quickly tend to drink more coffee to reach the same effect, and people who are sensitive to it tend to drink less or stop earlier in the day. That is why caffeine metabolism genes show up at the top of this score.

But coffee drinking is mostly culture, habit, availability, price, work patterns and taste. No genotype survives contact with those, which is why the measured prediction is near zero even though the underlying pharmacology is well established.

How to read a high or low score

As entertainment, and as a pointer to the caffeine metabolism page, which tells you something more concrete: how quickly your body is likely to clear caffeine, and therefore whether an afternoon coffee is likely to affect your sleep.

Variants in this score you can read on their own

This score includes a variant that this site also explains individually, where you can see what each genotype means on its own: Caffeine metabolism speed (rs4410790).

How much of this score your file covers

39 of the published score's 48 variants are present in a standard consumer DNA file (81%). The remaining 9 cannot be read from one, so a result computed here approximates the published score rather than reproducing it.

Common questions

Can my DNA tell me how much coffee I should drink? No. This score explains a fraction of a percent of how much coffee people actually drink. The caffeine metabolism result on this site is more useful, since it speaks to how fast you clear caffeine rather than how much you choose to consume.

Why do caffeine genes barely predict coffee intake? Because intake is driven mostly by habit, culture, work and availability. Genetics nudges the preference through how quickly you clear caffeine and how strongly you feel it, and that nudge is small against everything else.

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