Does "gluten-free" make you faster? Do athletes need to avoid gluten? There may be a common belief that gluten are bad for health and performance, but is this true for athletes who do not have celiac disease or irritable bowel syndrome? A recent study tried to find the answer.
The general public is increasingly avoiding gluten, because gluten are believed to be "bad" and a diet free of gluten is believed to be healthier. The majority of followers of a gluten-free diet have self diagnosed their condition. This trend has also spread to athletes who are now often eating gluten-free with the idea that this will help their performance. There were no studies in the literature that investigated the effects of gluten on performance in athletes who do not have celiac disease.
Individuals with celiac disease must avoid dietary triggers such as wheat (which contains the protein gluten). Such triggers have been shown to damage the barrier function of the intestine. In individuals who do not have celiac disease there is no evidence for health benefits or performance benefits by removing gluten from the diet. A recent study Ahead-of-Print in Medicine and Science in Sports and Exercise investigated the issue. Dr Trent Stellingwerff, one of the authors of the study, who works with elite athletes on a daily basis and is married to one, discussed some of the findings at the recent American College of Sports Medicine meeting in San Diego.
The new study
Dana Lis from the University of Tasmania (Australia) and colleagues compared the effects of a gluten-free or gluten containing diet on performance in non-celiac athletes. Thirteen competitive endurance cyclists (8 males, 5 females) with no positive clinical screening for celiac disease or history of irritable bowel syndrome participated in the study. Each participant performed the same protocol after a seven day gluten-containing diet or a 7 days gluten-free diet. The order of the diets was random. There was a 10 days period between the two diets to avoid any effect from one diet to carry over into the next.
Training and nutrition was controlled and the only difference between the two diets was the intake of 16 grams of gluten per day. The participants performed a time trial with both diets and complated several questionnaires about how they felt and whether they experienced any gastro-intestinal problems. A blood test was performed to study markers of inflammation.
There was no difference in performance between the two diets. There were also no differences in gastro-intestinal discomfort, or how the participants were feeling. In addition none of the markers of inflammation showed a difference between the diets.
Therefore the authors concluded that a gluten-free diet has no benefits over a gluten-containing diet in non-celiac athletes. It also had no negative effects. The authors advised that athletes seek evidence-based advice before adopting a gluten-free diet for non-clinical reasons to ensure that nutrition intake supports individualised and optimal fueling for sport performance.