Q&A with John McQuaid

John McQuaid, photo by Hannah McQuaid

John McQuaid is the author most recently of Tasty: The Art and Science of What We Eat, now available in paperback. He's also the co-author of Path of Destruction. A Pulitzer Prize-winning journalist, he has written for a variety of publications, including Smithsonian and The Washington Post. He lives in Silver Spring, Maryland.

Q: Why did you decide to write a book about taste and flavor?

A: As I describe in the book, I became both frustrated by and fascinated by my kids’ divergent tastes. From an early age, my son liked hot peppers, he tended toward the extremes, and my daughter preferred white foods, comfort food like…mac and cheese. 

This became very frustrating, we couldn’t feed the kids the same things, there were [concerns about] nutritional issues, each was very picky. I began to think about why they diverged—they had similar genes and were in the same place. I became interested, and began delving into the topic.

Q: You start the book by discussing the once-famous, now somewhat discredited “tongue map.” What is the significance of the rise and fall of this map?

A: It’s kind of fascinating because this map became quite popular in the last couple of generations. It showed the tongue divided in different areas. There were thought to be four of them: sweet, bitter, sour, and salty. This became a fixture in elementary school science experiments.

As molecular biology developed, scientists began to wonder where does this come from—it doesn’t comport with what we’re finding. They found that all parts of the tongue could sense all tastes, though not all equally.

I looked into where did the map come from—there have been a few scientists who had researched the issue. One traced it back to an experiment done around 1900, and somehow there was a scientific game of “telephone”—another scientist exaggerated the differences the first guy found, and somehow that transmogrified into the map. It was totally wrong, but it caught on.

Q: You write, “Flavor remains frustratingly paradoxical.” What are some of the main reasons for this?

A: In researching this, I got frustrated because so many answers point in two or three directions at once. It is a complicated, human phenomenon conditioned by biology, but also our culture and family background. These things are interacting with our biology in many different ways.

The most basic one is that people like stuff that’s objectively bad-tasting, with a bitter taste or hot-chili-pepper hotness. Nobody has a biological, neuroscientific explanation for this. Nobody has nailed that question.

When you get into more cultural/psychological domains, there are better explanations for this. The most common explanation for why people like superhot chili peppers was found by Paul Rozin—people like a little aversion in their lives because it gives them a thrill…like riding a roller coaster. In the last 30 years, there has been no better explanation.

Q: How much are someone’s flavor preferences likely to change over the course of their lifetime?

A: It’s constantly changing in kids. Kids are constantly changing. There are new connections forming in their brains, and old ones disappearing. Their biology is changing, and that influences their taste.

The most common problem is picky eating—it’s so universal. There are many speculative explanations for that, but no one has come up with a super-good one. Maybe [it comes from] hunter-gatherers; no one wants a toddler stuffing [unknown] berries in their mouth.

Many kids have a strong sweet tooth, and that declines as we get older. As we get older…there’s a stronger social dimension that influences our tastes.

The human palate has great flexibility. We can learn to like almost anything. If we move to a different country, or a different part of this country, we will develop [new] tastes. There’s a complex interaction with what age you are, and who you’re hanging out with.

Q: You write, “Taste and smell blend so seamlessly in flavors that the different senses merge, becoming indistinguishable.” Why is this?

A: Another interesting basic question the book tries to get at is what is flavor between human and animal? In humans, we have the merging of taste and smell, all the senses, the idea of the human mind wrapped up in flavor; an animal is somewhat different.

The parts of the [human] brain that handle taste and smell are distinct, and yet they overlap and are integrated. There’s different information entering the brain through different synaptic [paths], but it combines into something greater than its parts.

Also, the shape of the head when you chew: taste is experienced on the tongue, and aroma is passed through…a short pathway. As a result, we experience that form of smell more powerfully than other animals [with longer pathways] do. Smells tap into primal features of the brain, like memory and instinct.

Q: What is the “miracle berry” and do you see a larger impact for it in the future?

A: The miracle berry is a berry which contains a substance known as miraculin. People make it into paste, or it can be a pill. It affects the sensation the tongue experiences. It changes sour into sweet. It’s also suppressing the sweet taste a little.

It changes the flavors of whatever you’re eating if it contains acid and sugar. It makes lemons taste like lemonade, it makes limes taste like oranges, and it makes sour cream taste like cheesecake. It’s an interesting natural sweetener.

I interviewed a chef in Chicago who was trying to build on this sensation. He founded a restaurant and then a coffeeshop. His hope is to build on this because it’s a naturally occurring substance that can fool the brain into [eating] less sugar. I don’t know how marketable this is, but it has interesting potential.

Q: What surprised you most in the course of your research?

A: I was surprised at how infinitely flexible it is--you think of taste as being a chemical sensation. You taste something on your tongue and your brain has a reaction.

[It’s] flexible because it’s shaped by other forces—your memories of past meals, what you think about what you’re eating, how something looks, the price of it, the people you’re with—it all shapes your taste experience. It does change the nature of the experience.

Also part of what makes it flexible is it’s able to be manipulated by product placements. It cuts against what we think taste is.

Q: How have readers responded to your book?

A: Very enthusiastically! I have gotten interesting feedback from chefs, flavor scientists, neuroscientists, foodies, and high school students.

Q: What are you working on now?

A: Other than book promotion? I’m trying to come up with another book idea.

Q: Is there anything else we should know about the book?

A: I tried to write about stuff I found interesting that I hoped other people would. What I found interesting—it does reach into all those other areas like our social nature, commerce, neuroscience vs. genetics, all these things that shape who we are.

--Interview with Deborah Kalb. For a previous version of this Q&A, please click here. John McQuaid will be participating in the Bethesda Literary Festival, which runs from April 15-17, 2016, in Bethesda, Maryland.