If talk show host Jimmy Kimmel’s recent informal poll proved anything, it’s that without even knowing what gluten is, some people will do anything to avoid it.
However, a new study from researcher and Director of Gastroenterology at the Alfred and Monash University in Australia, Peter Gibson, may have these interview subjects–and you–thinking twice before banishing the bread and cookies.
The Origins of Gluten-Free
First, some context: Gluten, a protein found in grains like rye, wheat, and barley, is most definitely a threat to the estimated 1.8 million Americans diagnosed with celiac disease. For celiac sufferers, gluten causes inflammation of the small intestine and prevents the absorption of important nutrients.
Ironically, Gibson was one of the pioneers of the gluten-free movement. In 2011, he published a game-changing study that suggested gluten could be problematic even for people who don’t suffer from celiac disease. Gibson’s findings suggested that anyone experiencing symptoms of irritable bowel syndrome (pain, bloating, gas, diarrhea, constipation) could have “non-celiac gluten intolerance” and potentially benefit from a gluten-free lifestyle.
The public paid attention: Three years after the study, 30 percent of Americans say they’d like to eat less gluten, 18 percent buy gluten-free products, and sales of gluten-free foods are estimated to hit $15 billion by 2016.
What’s the Real Culprit?
Now, Gibson admits he may have been wrong about gluten. In a new sample study involving 37 subjects who had non-celiac gluten sensitivity, he found that each reported worsened gastrointestinal symptoms whether they were fed high-gluten, low-gluten, or control diets. The only time these participants reported feeling better was when they consumed a diet low in Fermentable, Oligo-, Di-, Mono-saccharides and Polyols, or FODMAPs.
If the average pedestrian is unsure how to define “gluten,” then “FODMAPs” definitely need some explanation. FODMAPs are short-chain carbohydrates and alcohols that are poorly absorbed in the small intestine. You’ll find them in everything from asparagus and cabbage to apples and–yes–wheat. Low-FODMAP diets are commonly prescribed to IBS sufferers.
All in Your Head?
For the first two weeks of Gibson’s most recent study, participants were fed a baseline diet low in FODMAPs. During this baseline diet, all participants reported feeling less gastrointestinal problems. After the two weeks, the subjects were blindly assigned to either a high-gluten, low-gluten, or the same low-FODMAP baseline diet.
All the subjects rotated through all three diets without knowing which one they were on at any given time. Gibson found that they all reported more gastrointestinal distress, no matter which diet they were on. The subjects were experiencing a “nocebo” effect–suffering from symptoms even without the presence of the supposedly harmful substance. In other words, the assumption that they were eating a harmful diet was enough to make them feel sick. Gluten itself wasn’t to blame.
The FODMAP-Gluten Link
But is there a legitimate reason people report feeling better when gluten is off the table?
“A lot of folks who test negative for celiac disease nevertheless believe they are gluten sensitive,” says One Medical Group’s Malcolm Thaler, MD. “After all, they eliminate sources of gluten from their diet and they feel better. Some or even many of them may be right. But in eliminating gluten sources from their diet, they are also eliminating other foods that may be the true culprits.”
It just so happens that many FODMAP-containing foods also happen to be gluten-heavy. Cereals, breads, noodles, pasta, and pastries are all loaded with FODMAPs and gluten.
“Whether it is FODMAPs or something else causing symptoms, it is clear at least from this small study that gluten sensitivity may be overrated,” Thaler says.
More research is necessary to determine whether gluten really has gotten a bad rap, but in the meantime, Thaler advises anyone experiencing gastrointestinal distress to see a health care provider before self-diagnosing. “This study matters because it affects what people choose to eat,” he says. “And what people eat has a large impact on the quality of their lives.”