Two years ago, at the recommendation of a nutritionist, I stopped eating wheat and a few other grains. Within a matter of days the disabling headaches and fatigue that I had been suffering for months vanished. Initially my gastroenterologist interpreted this resolution of my symptoms as a sign that I perhaps suffered from celiac disease, a peculiar disorder in which the immune system attacks a bundle of proteins found in wheat, barley and rye that are collectively referred to as gluten. The misdirected assault ravages and inflames the small intestine, interfering with the absorption of vital nutrients and thereby causing bloating, diarrhea, headaches, tiredness and, in rare cases, death. Yet several tests for celiac disease had come back negative. Rather my doctors concluded that I had nonceliac “gluten sensitivity,” a relatively new diagnosis. The prevalence of gluten sensitivity is not yet clear, but some data suggest it may afflict as many as 6 percent of Americans, six times the number of people with celiac disease.
Although gluten sensitivity and celiac disease share many symptoms, the former is generally less severe. Compared with individuals with celiac disease, people with gluten sensitivity are more likely to report nondigestive symptoms such as headaches and do not usually suffer acute intestinal damage and inflammation. Lately, however, some researchers are wondering if they were too quick to pin all the blame for these problems on gluten. A handful of new studies suggest that in many cases gluten sensitivity might not be about gluten at all. Rather it may be a misnomer for a range of different illnesses triggered by distinct molecules in wheat and other grains.
“You know the story of the blind man and the elephant? Well, that's what gluten-sensitivity research is right now,” says Sheila Crowe, head of research at the gastroenterology division at the School of Medicine at the University of California, San Diego. As doctors continue to tease apart the diverse ways that the human body reacts to all the proteins and other molecules besides gluten that are found in grains, they will be able to develop more accurate tests for various sensitivities to those compounds. Ultimately clinicians hope such tests will help people who have a genuine medical condition to avoid the specific constituents of grains that make them ill and will stop others from unnecessarily cutting out nutrient-dense whole grains.
Seeds of Sickness
Among the most commonly consumed grains, wheat is the chief troublemaker. Humans first domesticated the wheat plant about 10,000 years ago in the Fertile Crescent in the Middle East. Since then, the amount of wheat in our diet—along with all the molecules it contains—has dramatically increased. Of all these molecules, gluten is arguably the most important to the quality of bread because it gives baked goods their structure, texture and elasticity. When bakers add water to wheat flour and begin to knead it into dough, two smaller proteins—gliadin and glutenin—change shape and bind to each other, forming long, elastic loops of what we call gluten. The more gluten in the flour, the more the dough will stretch and the spongier it will be once baked.
Until the Middle Ages, the types of grain that people cultivated contained far smaller amounts of gluten than the crops we grow today. In the following centuries—even before people understood what gluten was—they selectively bred varieties of wheat that produced bread that was lighter and chewier, inexorably increasing consumption of the protein. As technology for breeding and farming wheat improved, Americans began to produce and eat more wheat overall. Today the average person in the U.S. eats around 132 pounds of wheat a year—often in the form of bread, cereal, crackers, pasta, cookies and cakes—which translates to about 0.8 ounce of gluten each day.