Dana Lis, PhD, is a Registered Dietitian, researcher, lifetime athlete and has a huge knowledge base on sports nutrition for optimizing athletic performance. Dana’s been involved in current research examining gluten-free and low-FODMAP diets for athletes, especially endurance athletes, which is the focus of this episode. You can reach Dana at www.summitsportsnutrition.com or on Twitter: @dlisforrest.

Intro & Why Our Guts Are At Risk

* Dana’s background and how she got involved in this area of research.

* The research shows perhaps we need to think twice about gluten as the cause of GI issues, and perhaps look more to FODMAPs as the problem.

* FODMAPs = Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols.

* “Available literature suggests that it is the reduced fructan and GOS quantity in a gluten-free diet that modulates GI symptoms and not gluten itself (Gibson and Muir 2013; Gibson et al. 2015).”

* The Monash FODMAP app and online resources

* Why does endurance exercise run the risk of causing gut issues (a refresher) and can we train ourselves to have a stronger gut?

* Takes 4 to 5 days for epithelial cells (the gut) to repair after a bout of endurance exercise; but athletes train more frequently than that.

* Increased intestinal permeability from exercise may lead to excessive absorption of gluten-derived peptides in NCGS, which could lead to immune-related responses.

* Dehydration and heat further compromise intestinal integrity.

* Altered digestion of short-chain carbohydrates may augment GI symptoms triggered during exercise.

* Despite some GI-adaptions in trained individuals, splanchnic blood flow is still reduced by up to 80% at 70% V02max (Qamar & Read, 1987).

* How common are GI issues? “Gastrointestinal (GI) symptoms are common in up to 70% of endurance athletes (de Oliveira & Burini, 2009), and aside from mechanical, psychological and physiological triggers, several dietary factors are believed to influence symptoms (de Oliveira et al., 2014).”

Gluten Research on Athletes

* Takeaways from the review article: “Commercial Hype Versus Reality: Our Current Scientific Understanding of Gluten and Athletic Performance.”

* “This diet has not been shown to affect either positive or negative competitive performance or symptoms of GI health and inflammation and/or nutritional status in NCA (non-celiac athletes).”

* But, in NCA, what if a GFD (gluten-free diet) makes someone feel better even if the science says “no difference?”

* What about athletes with subclinical conditions and reports showing how gluten increases inflammation, intestinal permeability, leaky gut and so on?

* “Exploring the Popularity, Experiences, and Beliefs Surrounding Gluten-Free Diets (GFD) in Non-Celiac Athletes (NCA)” show positive outcomes with a GFD, even if the placebo effect aka “belief effect” is at play.

* 910 athletes

* 59% follow a GFD less than 50% of the time (GFD < 50).

* 41.2% follow a GFD 50–100% of the time (GFD > 50), including 18-world and/or Olympic medalists. Predominantly endurance sport athletes.

* 84% of the GFD > 50 group indicated symptom improvement with gluten removal.

* Reasons why athletes adopted this diet (self-diagnosed vs medical condition); risks of the diet; positive outcomes reported; and conclusions.

* Meanwhile Dana’s study, “No Effects of a Short-Term Gluten-Free Diet on Performance in Non-Celiac Athletes” showed no difference and no positive effects of a GFD in healthy well-trained athletes.

* How this study was conducted and outcomes.