The Gene That Makes Cilantro Taste Like Soap Explains Almost None of It

A variant near a cluster of olfactory receptor genes is reliably associated with finding cilantro soapy. It is also a small effect in a trait shaped mostly by cuisine and exposure. Both facts are true, and the second gets less coverage.

Some people bite into cilantro and taste a herb. Others taste dish soap. The disagreement is unusually vehement for a leaf.

There is a genetic component, and it has a name.

The variant

Researchers ran a genome-wide association study on 14,604 people of European ancestry who had reported whether cilantro tastes soapy to them, then replicated the result in a further 11,851 participants.

The strongest association was rs72921001, sitting within a cluster of olfactory receptor genes on chromosome 11, close to OR6A2 — a receptor with known affinity for the aldehyde compounds that give cilantro its smell (Eriksson et al., Flavour, 2012).

That is a satisfying result. A smell receptor sits next to the variant that predicts whether a smell is repellent. The mechanism practically writes itself.

Now the part that usually gets cut

The effect is small. The variant explained well under one percent of the variation in whether people found cilantro soapy.

Put differently: knowing someone's genotype at rs72921001 barely helps you predict whether they will like coriander. Most soap-tasters do not carry the risk allele, and plenty of carriers eat it happily.

The paper found something else worth sitting with. The proportion of people who find cilantro soapy varies substantially by ancestry group — and the pattern tracks how much cilantro a food culture uses. In cuisines where it is everywhere, fewer people report the soapy taste.

Exposure appears to matter more than the receptor. Repeated pleasant exposure to a flavour reliably shifts how it is perceived, and that mechanism is not written in your genome.

Why this post exists

Cilantro genetics is one of the most-shared facts in consumer DNA testing, usually rendered as: there is a gene that makes cilantro taste like soap. The first half is true. The implied determinism is not.

It is a good test case for reading any genetic result. A real association, robustly replicated, with a plausible biological mechanism — and a tiny effect on any individual.

What the app reports

Ci-lantro vs No-lantro checks your genotype at the variants from the Eriksson study and tells you where you would have fallen among that study's participants had you been one of them.

If it says you should hate cilantro and you love it, the app is not broken and neither are you. It reports a small statistical tendency, not a verdict from your tongue.