Medical surveys indicate that less than 2 per cent of the population has coeliac disease or wheat allergies. These are the people who should be on gluten-free diets. Another 5 to 10 per cent have a clinical gluten sensitivity, and benefit from a gluten-free diet.
As you’ve probably noticed from water-cooler chatter and supermarket aisles, far more individuals have diagnosed themselves as gluten-sensitive, and undertaken a gluten-free diet. Indeed, a new study has found that 41 per cent of non-coeliac-athletes follow a gluten-free diet much of the time. Of this group, 70 per cent reported that they are endurance athletes.
“I can’t say I was surprised by these numbers,” co-author Dana Lis, a nutrition Ph.D., told Runner’s World this week. “I saw a lot of it in my work with athletes before the London Olympics. I was more surprised at how strongly the athletes believed in the diet, without any scientific backing.”
About 10 per cent of the 910 athletes who responded to the online survey were World Championships or Olympic medallists, but the majority were recreational athletes. Many began a gluten-free diet because they had gastrointestinal problems.
The paper divided non-coeliac, gluten-free athletes into two groups: one practiced the gluten-free diet less than 50 per cent of the time, and one more than 50 per cent. Members of the second group were more likely to report improved exercise performance, decreased illness, decreased gastrointestinal distress, and improved body composition.
Remember: None of these athletes had a medical diagnosis indicating they should be on a gluten-free diet. And that’s a concern to Lis, from Australia’s University of Tasmania, and her co-researchers. They believe the reported results may result from a strong placebo effect, and that there are potential downsides to a gluten-free diet. A big one, for endurance athletes, may be lowered carbohydrate intake.
“Many athletes are self-diagnosing this condition when other factors may be the cause,” said Lis. “This could present risks. You’d face problems while travelling and competing abroad, you might not reach your optimal fuelling, and you could be low in fibre, iron, some B vitamins, and certain probiotics.”
Lis would prefer that athletes with gastrointestinal problems seek other solutions before launching themselves into a gluten-free diet. In particular, she suggests a thorough medical work-up and an appointment with an experienced sports nutritionist.
“[Gastrointestinal] problems can be very complex, and it’s important to look at them systematically,” she said. “That’s the best way to ensure that underlying problems are not overlooked, and that solutions are successful for the long term.”
