Is gluten-free a fraud or your key to being a better athlete?
Is gluten-free a fraud or your key to being a better athlete?

The Surprising Reason Gluten-Free Diets Actually Work

You’ve been told that gluten-free diets are a fraud, that the science is settled, and that it’s all just the placebo effect. If so, how can the anecdotes be explained? Enter FODMAPs, the underappreciated forms of sugar that may just underpin your wheat, rye, and barley intolerance—and unlock your fitness potential.

Is gluten-free a fraud or your key to being a better athlete?
David Despain

Outside's long reads email newsletter features our strongest writing, most ambitious reporting, and award-winning storytelling about the outdoors. Sign up today.

Gluten-free diets shouldn’t work. The science, as shown by recent research, isn’t on their side. But talk to the athletes who willingly deprive themselves of gluten (a protein found in wheat, rye and barley) and they’re likely to respond with miraculous tales: gone are their days of feeling bloated and fatigued. They’ve lost weight. They recover faster. And they’ve never felt better. Can they really all be deluding themselves?

As often is the case with nutrition, yes but also no. Gluten-free diets are indeed making people feel and perform better. But it likely has little to do with gluten. Instead, researchers from Australia believe they’ve found the true culprit in the form of fermentable sugar components, otherwise known as FODMAPs (fermentable oligo-di-monosaccharides and polyols, in case you were wondering). One of the most potent kinds, fructans, are poorly absorbed in the gut—and they just happen to be found in the same culprit foods that contain gluten: wheat, rye and barley.

Originally developed to help irritable bowel syndrome (IBS) patients in the late 1990s, a diet low in FODMAPs has increasingly proven itself effective in managing symptoms of the disorder, if not widely known among the general population, says Susan Shepherd, an advanced accredited practicing dietician, senior lecturer at LaTrobe University, Melbourne, and one of the original proponents of the diet.

And this is where things get interesting. “The low-FODMAP diet has also been shown to be more effective than a gluten-free diet in improving gastrointestinal symptoms in people without celiac disease,” Shepherd said.

In other words, going low-FODMAP—which, in practice, also means essentially going gluten-free—can eliminate the worst symptoms people associate with gluten intolerance: abdominal pain, bloating, gas, diarrhea, and/or constipation.

This is huge for athletes who’ve previously benefited from “gluten free,” Shepherd said. For one, by adopting a low-FODMAP diet athletes can decrease any gastrointestinal symptoms on training and competition days, which affect nearly one in seven people and up to 80 percent of athletes. For two, it can help decrease fatigue and lethargy and improve concentration. FODMAPs cause tiredness and lethargy in up to 73 percent of people.

“Achieving one and two has the potential to have a very significant positive impact on sports performance,” Shepherd said.

That’s certainly a provocative stance, but it’s gaining credibility—and attention. Dr. Peter Gibson and Jessica Biesiekierski of Monash University, Melbourne, Australia, who are often credited with starting the whole gluten-free craze are now saying FODMAPs are the more likely cause of symptoms in those who have self-reported non-celiac gluten sensitivity (NCGS).

In 2011, it was their study that provided evidence for the 1980s-proposed existence of NCGS. Another pilot study from Dr. Alessio Fasano, founder of Massachusetts General Hospital’s Center for Celiac Research, corroborated their findings. Then, the word spread rapidly that “gluten free” could improve the health of others beyond those diagnosed with celiac, a notion further popularized by low-carb and “paleo diet” followers and the publication of a few diet books. Soon enough, food marketers took notice. Mintel, a global marketing research firm, reports that the U.S. market for “gluten free” foods had 44 percent growth between 2011 and 2013 with no signs of slowing down despite only 1 percent of the population having celiac disease.

But as journalist Ross Pomeroy recently reported, Dr. Gibson and Biesiekierski performed more research that appears to have overturned initial findings. In 2013, their double-blind crossover trial evaluated gluten versus other potential dietary triggers like FODMAPs in NCGS and IBS patients that all but obliterated the conclusions of the first study. In another study published just last month, they found that one in four people who claimed they had gluten sensitivity actually had symptoms that were more likely related to FODMAPS.

That doesn’t necessarily mean that NCGS doesn’t exist at all, but that many people have misattributed their symptoms to the syndrome. There’s a major difference between the food intolerance symptoms of FODMAPs (gas and bloating) and gluten sensitivity, according to Dr. Fasano. “Comparing a reaction to FODMAPS and gluten sensitivity is like comparing apples to oranges,” he said.

Food intolerances (think: lactose or FODMAP), he explains, is caused when the body lacks the proper digestive enzymes or when they are too abundant to be fully absorbed. In contrast, a food insensitivity (think: gluten) is an immune reaction to a component in food, typically proteins, which cause both symptoms in the gut and elsewhere in the body.

“With gluten sensitivity, we are at the same point where we were with celiac disease 20 years ago. That is, we have many more questions than answers and, as our colleagues from Australia state, much more research is needed,” he said.

But for athletes and others who’ve noticed an improvement while going “gluten free,” the Australian research clearly points to what’s affecting their guts on a broader scale: FODMAPs.

Monash University has produced an app to help with avoiding high-FODMAP foods. Shepherd is also behind a new certification logo “FODMAP Friendly,” which is registered internationally, including in the U.S.

promo logo