Special Diets

The gluten-free diet is swelling in popularity with athletes: one study found that out of nearly 1,000 competitive athletes in Australia, 41% were following a gluten-free diet. This could be because some athletes experience bloating and other gastrointestinal symptoms during and after exercise, and believe eliminating gluten from their diet will help. But does a gluten-free diet really make a difference? A first-of-its-kind study discovered that, at least in the absence of pre-existing gluten-related health problems, it may not. The study was published in Medicine & Science in Sports & Exercise and included 13 competitive cyclists with no history of celiac disease, gluten sensitivity, or irritable bowel syndrome. For the first seven days of the study, all the cyclists ate a gluten-free diet supplemented with nearly identical sports bars that either contained 16 grams of gluten or were gluten-free. After a ten-day wash-out period, the cyclists resumed the gluten-free diet and switched to the opposite sports bar (those who had eaten a sports bars with gluten now ate gluten-free bars and vice versa) for another seven days. Throughout both seven-day trial periods, the cyclists continued their normal training routines and answered daily and post-exercise surveys that included questions about their well-being and gastrointestinal symptoms. At the end of each trial period, every cyclist completed a strenuous 45-minute ride followed by a cycling time trial to test their performance. Researchers took blood samples before, between, and after the cycling tests to measure markers of intestinal and general inflammation. They found that:

• There was no significant difference in athletic performance between cyclists eating the sports bar with gluten and cyclists eating the gluten-free sports bar.
• The cyclists’ self-reported digestive symptoms and daily well-being were similar when consuming gluten-free and gluten-containing sports bars.
• There were no differences in post-exercise inflammatory markers between cyclists on gluten-free and gluten-containing bars.

These findings reveal that a gluten-free diet may not help or hinder athletes without gluten-related health issues in the short term. More research is needed in larger populations and over longer periods of time to understand if the findings apply to other groups of people, and to see how a gluten-free diet could affect athletes over the long term. If you’re experiencing gastrointestinal symptoms, whether they are exercise-related or not, it might be a good idea to see a nutritionist or healthcare practitioner to get evaluated for gluten-related disorders or other health conditions; but if you are symptom-free, gluten-free isn’t necessarily a healthier diet.

Source: Medicine & Science in Sports & Exercise