Supertaster

This ran today in the Herald Journal Arts section:

I've always known that my husband is a super hero. He washes dishes. He wrestles on the floor with the kids. Our yard is gorgeous thanks to him (and a lot of help from Anderson's Seed and Garden). But he has a secret. He's tried to conceal it, but a wife can always tell. I think he is a supertaster.

The guy's food preferences flummox me. He despises cheese, but he likes yogurt. He enjoys healthy fare like broccoli and fish, but he would rather chew on a wicker basket than eat whole wheat. He enjoys sugar-dense treats like divinity and fudge, but doesn't like apple pie. And when I say he doesn't like, I mean if there were a thermo-nuclear explosion incinerating all food from the face of the earth except for one warm, fresh-baked, sweet-tart caramel apple pie with a flaky lattice crust and melted sugar on top, he still wouldn't eat it.

Sometimes I just sit at the kitchen table and stare at him.

I know I'm not alone. You probably know someone who has “particular” food preferences, or you may have your own peculiarities about what you put in your mouth. Some preferences come from the way we are raised. If our mothers (or our cultures) tell us that tomatoes taste good, chances are they eventually will. But not all variation in food preference can be accounted for this way.

Scientists have discovered that people live in different sensory worlds. In 1931, a DuPont chemist (who was probably married to a picky eater) discovered that a certain chemical tastes bitter to some people while others found it tasteless. Foods that taste nutty and mild to one person may taste acrid and bitter to another. Some people, supertasters, experience bitter flavor with greater intensity than average.

To find out if my husband is a supertaster, I brought him to meet Dr. Silvana Martini, assistant professor in the Department of Nutrition and Food Science at Utah State University. Martini spends her days thinking about the way people taste food.

Martini tested us by having us taste seven little pieces of filter paper saturated with increasing amounts of the bitter chemical propylthiouracil (PROP). At the lowest level, about 25 percent of the population (supertasters) can taste the bitter. About half the population tastes nothing until the middle and higher levels of the concentration. About 25 percent of people taste nothing, even at the highest levels (non-tasters).

It didn't go like I planned it. I noticed a strong bitter flavor at the second level. My husband popped paper after paper into his mouth, completely unaffected by the PROP flavor. I tried level four, just to make sure I had tasted the right thing, and had to spit out the tinny acrid wad and rinse out my mouth. He tasted nothing, even at the most intense level. I am a supertaster, and my husband is a non-taster. He can't taste PROP at all.

The fault is in his genes. Genes create (or don't) something called fungiform papillae on our tongues. These mushroom-shaped tastebuds can sense bitter chemicals. If you have a lot of these tastebuds, you can taste the bitter in foods like broccoli and soy, and you are a supertaster. If you don't have these receptors, you don't taste the bitter, even though it still crosses your tongue.

Bitter is an acquired taste. Children don't like bitter flavors because they are still relying on their genes to tell them what tastes good and what doesn't. To our genes, sweet tastes good because we are hard-wired to know that our body needs sucrose for energy. Salty is pleasant because our body knows it needs sodium chloride for equilibrium in our cells. We like the savory flavor umami (oo-mah-mee) because it means the food contains monosodium glutamate … a flavor our genes interpret as protein.

Sour and bitter are the ugly stepchildren of flavor. Our genes associate these two flavors with poisonous plants. Just give a baby a grapefruit, and in her response you can see our genes at work, trying to keep us from killing ourselves by ingesting bitter substances like strychnine.

But obviously there are many foods that taste bitter and won't put us in our grave. Our brains learn this through experience, said Martini. As we grow, our brains override our genetic wiring and we begin to enjoy the bitter flavor of grapefruit, coffee, and dark chocolate.

So why do I, the supertaster, tolerate lots of different types of foods, and my husband, the non-taster, stick with his “particular” cuisine? Studies show that being a supertaster is actually not very useful in predicting whether a person will be a picky eater, said Martini. Taste is complicated. In addition to the marriage between genetic disposition and experience, there is a world of other variables that play part. The whole olfactory thing for instance. The majority of nuanced flavor comes through our nose. Just like taste, what individuals smell may be actually different (from what the receptors in our nose are able to pick up) or interpreted differently by the brain.

And then there is texture. And habit. And psychology. And food availability. And health. And the manner in which you chew, swallow, and ponder your food. And good old fashioned bad vibes (I will never eat another fresh cherry without thinking of that one summer when my neighbor forgot to spray the tree).

So we can't use flavor as a predictor of food preference. But we can expand our communication about food to others, said Martini. You can learn to think about what you are eating and try to develop a vocabulary to better express your experience, she said. The researchers at Martini's lab are trained for six months in taste vocabulary before they even start eating cheese (in a research setting, anyway).

Even though he isn't a supertaster, any husband willing to come and taste filter paper for his wife really is a super hero. I'll leave him to his bag of peppered beef jerky and soda today because no matter what he likes to eat, I know he has good taste. He married me.