Illustration of a cartoon sun over a row of wheat stalks

Issue No. 133: What exactly is gluten, anyway?

Think of a powdered food like ground cinnamon or cornmeal. What do you get if you add it to some water and mix them together? Something like a paste. Now imagine the powder is wheat flour. Mix it with water and it creates a dough that holds together, yet stretches. What makes wet wheat flour different than all those other powders? Gluten!

Gluten is a mix of proteins.

Notably, it includes a special pair of proteins called gliadin and glutenin. When wheat flour is mixed with water, glutenin molecules join to form long, springy strings that make dough elastic—it stretches. At the same time, gliadin molecules bond between the glutenin molecules to make the dough plastic—it holds together. Together, these proteins form gluten: stretchy sheets that trap air bubbles created by a leavener like yeast. When baked, the dough solidifies around those air bubbles, creating the light, airy texture we expect of breads and pastries.

Outside of rye and barley, which can form a bit of gluten, no other grains contain gluten-forming proteins. Since wheat produces by far the strongest gluten, these days “wheat” and “gluten” are almost synonymous. While the term “gluten” dates back just a few centuries, we have been cultivating wheat for its ability to make stretchy doughs that bake into light, airy breads for 10,000 years. In other words, we’ve been growing wheat because of its gluten.

So what happened? While avoiding gluten is essential for folks diagnosed with celiac disease, for the 99% of us without celiac, there’s little to no scientific evidence to indicate that gluten is a health concern. So why is gluten free such a thing these days?

I have two theories about our current relationship with gluten.

The first one is about modern flour and its culinary cousins. White wheat flour is highly processed and gets lumped in with other processed, high-calorie, low-nutrition foods like sugar. There’s something to be said about white flour’s over-processing. And, like sugar, its abundance in our diet is a bit suspect. But it’s probably not gluten’s fault.

My second theory is that we just want simple answers about how to be healthy. Easy, black and white rules of “eat this, don’t eat that, and you’ll be good to go.” It feels harmless to say “Hey, if gluten should be avoided by some people, we probably all ought to avoid it, right?” It makes me wonder though: why does gluten get all the attention? Why aren’t we all avoiding peanut butter because a small percentage of the population has a peanut allergy?

We have a long history of these sorts of restrictive dietary guidelines in America. Back in the mid-19th century, minister Sylvester Graham preached against consuming meat, alcohol, fatty foods, and white breads for fear that they’d lead to gluttony, lust, and materialism. He had so many followers that they had a name: the Grahamites. On the one hand, Graham was mostly wrong. But then again, he did also invent the graham cracker, and I’m grateful for that every time I eat a s’more. And hey, who knows. Maybe right now there’s a brand new, gluten free food being invented that, by the 2160s, will be a childhood favorite, long after we’ve forgotten that it was created to avoid gluten.

Further gluten reading

For more details on the chemistry of glutenin and gliadin, there’s no better resource than Harold McGee’s exceptional On Food and Cooking.

For practical tips on how to make best use of gluten in your baked goods, refer to Shirley Corriher’s Cookwise.

For insight into gluten intolerances—and loads of other interesting learnings about the human body—check out James Hamblin’s If Our Bodies Could Talk.