Episode 7 · MAPASGEN · Free Material
Approximately one in seven people on the planet cannot stand coriander — for them it does not taste like a fragrant herb, it tastes like soap. This is not a preference and not upbringing. It is a variant of the OR6A2 gene, which encodes an olfactory receptor sensitive to aldehydes — the very molecules that give coriander its distinctive aroma. Carriers of a particular variant of this gene perceive those same aldehydes in a completely different way — and are entirely sincere in their inability to understand how anyone eats the stuff.
Coriander is just one of hundreds of examples of how genetics shapes taste preferences. Coffee, alcohol, bitterness, spice, sweetness — each of these sensations is underpinned by specific genes whose variants are unevenly distributed across the population. Your palate is not just habit. It is biochemistry.
Caffeine is metabolised in the liver by the enzyme CYP1A2, encoded by the gene of the same name. Its activity varies dramatically between individuals depending on the gene variant.
A historical note: Honoré de Balzac reportedly drank up to 50 cups of very strong coffee a day — without it, he claimed, he could not write. He died at 51 of heart failure. Whether he was a slow CYP1A2 metaboliser, we cannot know. But his case illustrates how differently organisms handle the same substance.
The TAS2R38 gene encodes a bitterness receptor. Its variants determine how intensely you perceive bitter compounds — in particular PTC (phenylthiocarbamide) and PROP, as well as many natural bitter flavours in broccoli, Brussels sprouts, grapefruit, and dark beer.
A practical takeaway: If your child categorically refuses broccoli, they may well be a supertaster who literally perceives it differently from you. This is not defiance. It is the genetics of taste receptors. |
Alcohol is metabolised in two steps. First, the enzyme ADH (alcohol dehydrogenase) converts ethanol into acetaldehyde. Then ALDH2 (aldehyde dehydrogenase) converts the toxic acetaldehyde into harmless acetate.
Approximately 36% of East Asian populations carry the ALDH2*2 variant, in which the second enzyme barely functions. Acetaldehyde accumulates, causing facial flushing, elevated heart rate, and nausea. This 'Asian flush' is not an allergy to alcohol — it is a disruption of alcohol metabolism.
Importantly: carriers of ALDH2*2 who drink regularly have a significantly elevated risk of oesophageal cancer — precisely because of acetaldehyde accumulation, which is a known carcinogen.
— Continued in PRO Material —
The PRO material contains the test 'Your Hedonistic Profile': 8 questions about your taste preferences with an explanation of the likely genetic variants behind each, and how to find these markers in your own DNA test.
Premium contains a full longreid on spiciness: why capsaicin is pain rather than taste, how evolution made humans the only mammals that eat chilli peppers voluntarily, and what the TRPV1 gene says about your pain threshold.
MAPASGEN — the podcast about genetics that is already reshaping your life.