The consumption of gluten, the protein found in rye, barley, & wheat, leads to an autoimmune response damaging the small intestine in individuals with Celiac Disease. The resulting mucosal damage leads to nutrient malabsorption and The resulting mucosal damage leads to nutrient malabsorption and other concerns such as iron deficiency anemia, lactose intolerance,osteoporosis, GI distress, and weight loss. Some individuals experience non-Celiac Gluten Sensitivity (NCGS) which has overlapping GI symptoms to CD and IBS (e.g. bloating, diarrhea) and find some relief of symptoms by following a GF diet.
Interestingly, many non-Celiac athletes believe following a GF diet athletes (without celiac disease) believe a GF diet provides a performance benefit. In a sample of ~910 athletes, 41% reported following a GF diet 50-100% of the time despite only 13% being diagnosed with CD. Current research in non-Celiac athletes does not, however, indicate any improvement in performance, GI symptoms, well-being, inflammation or in immune function.
There are reasonable explanations as to why non-Celiac endurance athletes might avoid gluten to help with GI symptoms. Eating a gluten-free diet is associated with other dietary changes, such as FODMAP reduction, which may alleviate GI symptoms for some athletes. However, there are some risks to following a GF diet such as low fiber intake, vitamin and mineral deficiencies, high cholesterol and fasting blood glucose. Athletes looking into a GF or low gluten diet should seek assistance from a sports RD to ensure nutrient and energy needs are met.
•GF diets are appropriate for athletes with Celiac disease and possibly NCGS, & other auto-immune diseases.
•While there is no evidence that currently suggests a GF diet will benefit performance in non-Celiac athletes, athletes may perceive benefits of reducing gluten or experience improvement in GI symptoms by intentional or unintentional reduction in FODMAPs.
• Reducing high FODMAP foods (e.g. dates, figs, agave, honey, lactose, protein bars, some fruit juices and dried fruits, and certain nuts) before and during exercise may help alleviate GI symptoms even when gluten is still consumed.
PMID: 24901744; 25970665; 27399823, 30632437 , 31434299, 30671907, 29910298, 25583468