There is a great amount of discussion about whether individuals who do not have celiac disease should consume gluten-free diets. Gluten-free diets certainly have been a topic of discussion among athletes. Some athletes believe that consuming a gluten-free diet provides an ergogenic (performance-enhancing) effect, despite the lack of evidence to support this belief. In this Nutritionist’s View, I will first provide a definition of celiac disease and then present research that has been conducted in the area of consuming gluten-free diets.
WHAT IS CELIAC DISEASE?
Celiac disease, also known as celiac sprue, nontropical sprue, and gluten-sensitive enteropathy, is an autoimmune condition that, if not diagnosed, will lead to damage to the small intestine. In addition to damage to the small intestine, undiagnosed celiac disease can lead to iron deficiency anemia, early onset osteoporosis, lactose intolerance, and nervous system disorders, to name a few. Celiac disease typically is hereditary (1).
In individuals with celiac disease, the consumption of gluten, which is a protein found in rye, barley, and wheat, will lead to an autoimmune response, where the body will attack the small intestine, which will lead to malabsorption of nutrients. Therefore, individuals with celiac disease must avoid foods containing gluten (1).
Because of the increased diagnoses of celiac disease, there has been a rise in the production of gluten-free products. With this rise in availability of gluten-free products, there has been an increase in the number of individuals without celiac disease who now consume gluten-free products. Is there a basis for this? With respect to athletes, will consuming a gluten-free diet enhance performance? Let’s see what the research tells us.
GLUTEN-FREE DIETS AND ATHLETIC PERFORMANCE
Before discussing the effect of a gluten-free diet on athletic performance, it is important to understand why athletes choose to consume a gluten-free diet if they do not have celiac disease. Lis et al. (2) aimed to evaluate the demographics of athletes without celiac disease and ascertain the experiences and perceptions of why athletes choose to consume gluten-free diets. They administered an online survey to 910 athletes (528 women, 377 men, and 5 athletes who did not choose a gender). They reported that 41% of all athletes (18 of whom were world and/or Olympic medalists), consumed a gluten-free diet 50% to 100% of the time. A total of 13% consumed a gluten-free diet for management of a medical condition, whereas 57% of the athletes self-identified their gluten sensitivity. Athletes who consumed a gluten-free diet more than 50% of the time were mostly endurance athletes who reported gastrointestinal symptoms alone or in addition to other symptoms they believed were caused by gluten. More than 80% of the athletes who consumed gluten-free diets more than 50% of the time reported that their symptoms improved by removing gluten from their diets. Most of the athletes retrieved their information about gluten-free diets from online sources, coaches, and/or other athletes.
Lis et al. (3) conducted another study to evaluate the effects of consuming a gluten-free diet on exercise performance, gastrointestinal symptoms and injury, and inflammatory markers as well as perceived well-being among athletes without celiac disease. In this randomized, double-blind, crossover study, five female and eight male competitive cyclists, who did not have celiac disease, were provided either a 7-day diet that contained gluten or a 7-day gluten-free diet. These were separated by a 10-day washout period, at which point the athletes would receive the opposite diet.
Lis et al. (3) did not report any significant differences between the diets on exercise performance, in gastrointestinal symptoms during exercise, well-being, intestinal injury, or inflammation. Although this was a short-term study, with only 13 participants, it warrants that athletes need to be informed of the food choices they make on a daily basis.
Lis et al. (4) state that there are reasonable explanations between endurance exercise and gastrointestinal effects and why individuals may deem it beneficial to consume a gluten-free diet even if they do not have celiac disease. Nonetheless, the risk of dietary restriction and financial burden are just two factors that require further investigation on the consumption of gluten-free diets in athletes without celiac disease.
Although there is a paucity of research in the area of gluten-free diets and athletic performance, early research indicates there is no benefit for athletes who do not have celiac disease to consume gluten-free diets. More research is required in larger populations, and in different laboratories, to determine definitively if there is (or is not) a benefit.
Although there is a paucity of research in the area of gluten-free diets and athletic performance, early research indicates there is no benefit for athletes who do not have celiac disease to consume gluten-free diets.
2. Lis DM, Stellingwerff T, Shing CM, Ahuja KD, Fell JW. Exploring the popularity, experiences, and beliefs surrounding gluten-free diets in nonceliac athletes. Int J Sport Nutr Exerc Metab
. 2015;25(1):37–45. [Epub 2014 Jun 5].
3. Lis D, Stellingwerff T, Kitic CM, Ahuja KD, Fell J. No effects of a short-term gluten-free diet on performance in nonceliac athletes. Med Sci Sports Exerc
4. Lis DM, Fell JW, Ahuja KD, Kitic CM, Stellingwerff T. Commercial hype versus reality: our current scientific understanding of gluten and athletic performance. Curr Sports Med Rep