When it Comes to Food, Pickiness is in the Genes

I’ve always attributed my love of vegetables to the influence of my mother’s intense hippie years. When I was a baby, she avoided sugar-laden supermarket baby food, instead opting to feed me fresh broccoli that she grew and then mashed in a hand-cranked grinder.

But my much younger brother isn’t such a veggie fan, and I always figured it was because he came along in the years after Mom had relaxed her D.I.Y. dietary ideals and gotten friendlier with folks at Gerber. She never went so far as to let us have Captain Crunch, but we did get his healthier, creepier cousin, King Vitamin.

Regardless, it turns out that Mom’s efforts had little to do with our like or dislike of vegetables—or at least, not in the way that I thought. As humans, our sense of taste isn’t as much learned as it is genetically predisposed.

“Just like we all differ in our ability to see and hear, people differ in their ability to taste,” explained Danielle Reed of the Monell Chemical Senses Center in Philadelphia during an interview that aired this week on the PBS program Nova: ScienceNow, about the science behind picky eaters.

In fact, the geneticist Dennis Drayna at the National Institute of Health has pinpointed a single gene that may explain why my brother and I disagree on the awesomeness of Brussels sprouts. Taste receptors on the tongue are proteins made by our genes, and out of the thousands of genes in human DNA, there’s one that actually determines our reaction to the potentially bitter tasting compounds found in many plant-based food sources.

This gene comes from our parents in one of two varieties, described most simply as “non-taster” or “taster.” People with taster genes from both parents are very sensitive to bitter flavors in vegetables, while people with two non-taster genes can’t taste those particular bitter flavors at all. (People with one taster gene and one non-taster gene may taste some bitterness, but can learn to get over it and finish their veggies anyway.)

But there are more senses than just taste at work in the experience of eating. Our food’s texture, appearance and smell also play significant roles. Smell is particularly important; take away the olfactory sense, and the ability to taste is seriously hindered. Stuart Firestein, a biologist at Columbia University who has studied the sense of smell in mice, believes that our sense of smell actually decreases as we age, widening the variety of tastes that we can tolerate or even enjoy. I suppose this means that to a certain extent, the sophisticated palate many of us boast as we age is actually a dulled palate.

It also means that, despite our genetic differences, my brother and I may one day come to agree on the taste of brussel sprouts. I’m still waiting to see whether scientists can offer a genetic explanation for our differing tastes in music.

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