What this means

TRPV1 is the ion channel on sensory neurons that detects capsaicin (the active compound in chillies) as well as noxious heat. A common missense variant subtly changes channel sensitivity, which translates to small but measurable differences in perceived burn. The biggest predictor of spicy food tolerance is exposure, not genotype: regular chilli eaters desensitise to capsaicin over time regardless of which version of TRPV1 they carry.

TRPV1 is the sensor on your nerves that detects capsaicin — the heat in chillies — as well as actually burning-hot temperatures. A common DNA change tweaks how easily this sensor fires, which slightly changes how much burn you feel from spicy food. But the biggest thing driving spicy food tolerance isn't your genes — it's practice. People who eat chillies often get used to them over time, whichever version of TRPV1 they carry.

Caveats

• Tolerance is overwhelmingly learned. Habitual chilli eaters out-tolerate everyone else.
• The same gene also detects noxious heat, but pain-threshold effects are inconsistent.
• Studies of this variant show modest effect sizes.
• Spice preference is cultural and culinary, not really a "genetic taste".

References

• Caterina et al. — The capsaicin receptor: a heat-activated ion channel in the pain pathway (Nature, 1997)
• Kim et al. — Genetic influence on variability in human acute experimental pain sensitivity associated with gender, ethnicity and psychological temperament (Pain, 2004)