[The Science of Taste: How Your Spit Can Change Your Food Preferences]-[Spit-Take! The Science Of Saliva And Those Bitter Bites (Encore - 8/12/19)]

Wow in the World · B1 · 2019-08-12

📋 Summary

The Biology of Bitter: Why Your Palate Can Change

In this episode of Wow in the World, hosts Mindy and Guy Raz explore the fascinating biological connection between human saliva and our ability to tolerate—and eventually enjoy—bitter-tasting foods. By visiting a fictional, experimental eatery called "The Spit Take," the duo unpacks real-world scientific research that explains why children often detest vegetables like kale or Brussels sprouts, while many adults grow to love them.

The Bitter Truth About Taste Buds

As Guy Raz humorously notes during the show, he has become a self-proclaimed "kale crusader," despite having a strong aversion to such foods during his childhood. The hosts explain that out of the five basic tastes—salty, sweet, sour, umami, and bitter—bitter is universally perceived as the most unpleasant. This evolutionary trait likely served a protective purpose in human history, signaling potentially toxic substances. However, this same bitterness is found in some of the most nutrient-dense foods, such as dark chocolate, coffee, and leafy greens.

The Purdue University Experiment

To understand why our preferences shift over time, the hosts discuss a study conducted by Dr. Cordelia Running at Purdue University’s "Spit Lab" (formally known as the Saliva Perception, Ingestion, and Tongues Laboratory). The experiment involved 64 participants who were asked to consume chocolate milk—specifically a version with only 4% sugar, making it significantly more bitter than standard commercial chocolate milk—daily for a week.

Surprisingly, the study found that by the end of the week, the participants' perception of the bitterness began to decline. They didn't just mentally convince themselves to like the drink; their bodies underwent a physiological change.

The Role of Saliva Proteins

The core discovery of Dr. Running’s research centers on the composition of human saliva. The hosts explain that saliva is not just water; it contains "teeny tiny molecules called proteins." These proteins play a crucial role in how we perceive chemical flavors.

As the participants repeatedly consumed the bitter cocoa, their bodies responded by altering the production of these specific saliva proteins. Essentially, the spit glands learned to produce more of the proteins that act as a buffer, effectively "dampening" or decreasing the intensity of the bitter flavor. This biological adaptation suggests that repeated exposure to bitter foods actually changes the chemical makeup of our spit, which in turn alters the signal our taste buds send to our brains.

Conclusion: You Can Train Your Tongue

The episode concludes with a powerful takeaway: our food preferences are not fixed. While we may detest the taste of kale or broccoli as children, consistent exposure allows our biology to adapt. As Mindy puts it, "What we eat can, over time, determine the taste." This insight transforms the chore of eating one's vegetables into a scientific experiment, proving that with enough time and patience, even the most bitter foods can become a part of a healthy, enjoyable diet.

🎯Key Sentences

It's going to be a November to remember.

But for now, let's get on with the show.

This is giving me a headache.

What is all of this even about?

Well, I was just planning on taking it easy today.

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📝Key Phrases

music to your ears

take it easy

catch up on reading

rolling out the red carpet

put my finger on it

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📖 Transcript

Grownups, Wondery Plus subscribers can listen to Wow in the World early and ad-free right now.

Join Wondery Plus in the Wondery app or Wondery Kids Plus on Apple Podcasts.

Hey, Wowzer fans, Mindy here.

And before we start the show, I gotta let you know that this November, with a special new episode featuring our friends at Circle Round and Terrestrials on Radiolab for Kids,

And don't miss when Elmo from Sesame Street stops by Wow in the World to make us all belly laugh on November 24th.

Oh, but that's not all, Reg.

And parents, if you want to upload any photos or videos or messages to us, please visit wowintheworldcom and find a link where you can do just that, and if you haven't already done so, please subscribe on apple podcast or however you get your podcasts, leave us a few stars and a review and be sure to tell a friend about the show.

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