Supertasters and the Bitter-Taste Gene

Hand a group of people a strip of paper coated with a harmless bitter chemical and something curious happens: some grimace at an intense bitterness, while others taste almost nothing at all. That classic experiment traces back to a single bitter-taste receptor gene.

A famous taste test

For decades, researchers have used compounds called PTC and PROP to sort people into “tasters” and “non-tasters.” To tasters, a treated strip is unmistakably, sometimes overwhelmingly bitter. To non-tasters, it is close to flavorless. The split is remarkably clean, and it turns out to be largely down to genetics.

One receptor, three variants

The gene responsible is TAS2R38, which builds a bitter-taste receptor on your tongue. What matters is not one variant but a combination of three working together: rs713598, rs1726866, and rs10246939. Because they are usually inherited as a set, geneticists describe them as a haplotype - a package of variants that travels together.

Two haplotypes are common:

• PAV, the “taster” version, builds a receptor that strongly detects bitter compounds like PTC and PROP.
• AVI, the “non-taster” version, builds a receptor that responds only weakly.

You carry two haplotypes, one from each parent, so people fall along a range - two taster copies at one end, two non-taster copies at the other, and a middle ground in between.

What tasters notice

If you have the taster haplotype, a whole category of foods reads as more bitter:

• Cruciferous vegetables like broccoli, kale, and Brussels sprouts
• Black coffee
• Tonic water and other bitter drinks

This is one reason “I just do not like broccoli” can be more than stubbornness. For a strong taster, those vegetables genuinely carry a sharper bitter edge than they do for a non-taster sitting at the same table. The bitterness is not a flaw in the food - it is information your receptors are handing you, and tasters simply receive a louder version of it.

Supertasters are a bit different

You will often see “supertaster” used interchangeably with TAS2R38 taster status, but they are not quite the same thing. Being a supertaster is a broader sensory phenomenon - it involves overall taste intensity and even the density of taste buds on the tongue, not just this one receptor. TAS2R38 is a large, well-studied piece of the bitter story, but the full picture of a supertaster includes more than these three variants.

Why we taste bitter at all

Bitter perception is not an accident of cooking; it is a warning system. Many natural toxins are bitter, so a receptor that flags bitterness helped ancestors avoid eating something harmful. TAS2R38 is one of a whole family of bitter receptors built for exactly that job. Seen that way, a strong taster is not being difficult - they are running a more sensitive early-warning system, one that happens to fire on broccoli and coffee as readily as on genuinely dangerous plant compounds.

Reading it in your file

Because this trait rests on three markers, you would look up each rsID:

grep -E '^(rs713598|rs1726866|rs10246939)' my_raw_dna.txt

Interpreting a haplotype from raw letters is fiddly - the three positions have to be read together, and strand orientation can flip the letters - which is exactly the sort of thing a dedicated tool handles for you. You can explore taste-related variants with on device DNA analysis that keeps your file in your browser.

Bitter perception is a lovely example of genetics you can actually taste. The cilantro “soap” trait is a close cousin on the smell side, and if haplotypes and rsIDs are new, what SNPs are covers the groundwork.

This article is educational only and is not medical advice.