Not Just for Celiac

Why everyone can benefit from a gluten-free diet
By Mark Sisson

You’ve probably noticed by now that gluten-free is in. Restaurants are unveiling gluten-free menus and regular grocery stores are stocking gluten-free items. Your friends, your relatives, and your colleagues are talking about avoiding wheat and how they’ve benefited. Gluten-free diets, the “experts” love to say, are the biggest new dietary fad.

But why? What’s the deal with gluten, and why are so many people avoiding it? Should you try going gluten-free?

I’ll answer that last question first: yes. Yes, you should try it. Allow me to explain.

Gluten is a unique little protein. It’s found in wheat, rye, and barley, and it provides the viscoelastic properties that make wheat so attractive to bakers, pizza makers, pastry chefs, and processed-food conglomerates. It gives food bounce and chewiness and bite, many of the traits we’ve come to love in our baked goods.

But gluten has another interesting property. Upon digestion, it’s broken up into smaller protein fragments. These protein fragments are hard to digest for most people, so they tend to stay intact as they travel the length of the intestine. When an intact gluten fragment makes it to the intestinal wall, it triggers the release of zonulin, a biochemical messenger that increases intestinal permeability. It does this by telling the gut doorways (called tight junctions) which line and protect our intestine to open up and allow molecules to pass through into the bloodstream. Normally, intestinal permeability is tightly regulated, because if you open up the tight junctions indiscriminately, you’ll allow both good and bad stuff into the bloodstream.

If your gut is overly and indiscriminately permeable (or “leaky”), you end up with large protein molecules in your bloodstream. This causes your body to release antibodies that attack these potentially dangerous foreign proteins.

Unfortunately—since your body is made up of proteins that look an awful lot like the invading proteins your immune system is attacking—those same antibodies will attack your own tissues, joints, and organs. This is the definition of an autoimmune attack, a process that, if allowed to continue by constant gluten exposure, will develop into a full-blown autoimmune disease. And sure enough, chronic intestinal permeability is strongly connected to many autoimmune diseases including type 1 diabetes, rheumatoid arthritis, and multiple sclerosis, as well as seemingly disparate conditions like autism, eczema, and depression.

Researchers used to think that this reaction only happened in people with celiac sprue, a severe, relatively rare intolerance to gluten. But recent evidence suggests that gluten triggers the leaky gut response in anyone who eats it. The only difference is that celiacs suffer a sustained, extreme release of zonulin from gluten that results in chronic leaky gut, while for non-celiacs, the zonulin release is shorter-lived.

The problem is that wheat is a constant feature in our daily diets. We eat toast for breakfast, sandwiches for lunch, a roll at dinner, cake at parties, pizza while watching the game. In other words, nearly everyone in this country enjoys a steady infusion of gluten into our guts. Even if you aren’t celiac, daily intake of gluten means your gut is going to be permeable most of the time.

And the evidence is getting clearer and clearer with each passing day that far more people than the one in 133 that have celiac (a number that’s increased over the years) are at least partially sensitive to gluten. New studies are proving that non-celiac gluten sensitivity exists—that it’s a real clinical condition. They may not have the often-fatal reaction to tiny amounts of gluten that celiacs have, but they still suffer symptoms.

What’s almost worse is that—because they don’t have the obviously damaging response to gluten and often don’t even report any obvious symptoms—people with gluten sensitivity usually don’t even know it. They might get drowsy at midday, have persistent diarrhea, get sore joints whenever they exercise, or experience fogginess of mind from time to time, but they’d never think to connect it to the bagel they had for breakfast or the slice of pizza they ate at lunch.

Worst of all? The absence of obvious gastrointestinal symptoms doesn’t put you in the clear. Although changes in bowel habits, bloating, and stomach upset are the most common signs of gluten sensitivity, they don’t need to be present for gluten-induced leaky gut.

A common question is “How can wheat be so problematic if we’ve been eating it for so long?”

Well, first, we haven’t really been eating it for very long. For the bulk of human history, we were hunter-gatherers. For hundreds of thousands of years, humans and our ancestors ate wild game, fruits, nuts, tubers, and other forms of edible vegetation. The wild ancestors of cereal grains like wheat were too widely dispersed to gather in large amounts and took too much intensive processing before being edible to form a significant part of our diet. Around 10,000 years ago, the advent of agriculture allowed humans to start eating the ancestors of wheat and other grains in larger amounts, but for the vast majority of our existence, humans did not eat wheat.

Second, modern wheat is decidedly different than ancient wheat. About 60 years ago, wheat was bred to be shorter and stouter. This new dwarf wheat produced denser clusters of wheat berries on the same amount of land, thereby increasing yield and profits. But another unexpected change developed in this new dwarf wheat: the prevalence of the most allergenic gluten protein fragment. Whereas the gluten in old wheat contained less of the problematic protein fragment, the gluten in new wheat contained a greater proportion of this highly reactive fragment. The new gluten, then, is different from the old gluten.

Some genetic adaptation to grain consumption has occurred, particularly in populations with the longest grain-eating history, but gluten still causes problems in many—if not most—people. The difference is that, for most, the health problems are unpleasant, but manageable. They cause inflammation and poor digestion, but they won’t kill you outright. Many of the problems associated with gluten have become so normal and commonplace that people just assume they’re “part of everyday life.” Aches, pains, frequent bouts of diarrhea and constipation, midday brain fog: everyone gets this stuff, right?

It’s been my experience that a significant portion of people who decide to avoid gluten notice the immediate cessation of these and other “minor” health problems that they assumed would be with them for the rest of their lives.

Of course, you can do gluten-free the wrong way. If you replace the processed foods that contain gluten with gluten-free processed junk made of rice/corn/soy flour, processed seed oils, and heaps of sugar, you’re simply trading one poison for another. I hear from dozens upon dozens of people who never really felt much better, despite going gluten-free, until they realized this basic idea and began ditching all the processed food.

Once they began to look at gluten-free as a pathway toward better eating in general, they realized the benefits. Look at what happens when you stick to the foods we evolved eating: meat, fish, vegetables, fruits, roots, tubers, nuts, and healthy natural fats from animals, coconuts, and olives. You avoid gluten by default.

Focusing on simply avoiding gluten isn’t enough. You also have to fill your diet with healthful, nutritious, whole foods. Removing gluten allows your gut to heal so that it can absorb more nutrients and prevent harmful proteins from making it into your bloodstream, but you have to follow that up with the introduction of healthy foods full of nutrients. Otherwise, you won’t be doing anything with your newly restored healthy gut!


Mark Sisson is a fitness author and blogger, and a former distance runner, triathlete, and Ironman competitor. He has written several books that incorporate aspects of the popular Paleolithic diet, including The Primal Blueprint and The Primal Connection, out January 2013. He blogs at