The review, published in The Lancet, focuses on non coeliac gluten sensitivity (NCGS). This term describes people who experience intestinal or extraintestinal symptoms after eating gluten or wheat-based foods, despite not having coeliac disease or a wheat allergy. Around 10 % of adults worldwide now self report some form of gluten or wheat sensitivity, making this a relevant issue for cyclists who pay close attention to how diet affects both comfort and performance.
Most symptoms are not caused by gluten
The review was led by researchers from the University of Melbourne. By analysing results from carefully controlled dietary challenge studies, the researchers found that gluten is often not the true trigger.
“Contrary to popular belief, most people with NCGS aren’t reacting to gluten. Our findings show that symptoms are more often triggered by fermentable carbohydrates, commonly known as FODMAPs, by other wheat components or by people’s expectations and prior experiences with food,” said first author, Associate Professor Jessica R. Biesiekierski, PhD.
FODMAPs are basically carbs that are poorly absorbed in the gut and rapidly fermented by gut bacteria. Wheat contains both gluten and these fermentable carbohydrates, which makes it easy to point the finger at gluten when symptoms occur. When studies controlled for these factors, only a small proportion of participants showed symptoms that could be consistently linked to gluten itself. In many cases, reactions were no different from those caused by a placebo.
A gut brain interaction rather than a gluten disorder
Another important finding is how closely NCGS overlaps with irritable bowel syndrome. IBS is widely understood as a condition involving heightened gut sensitivity and altered communication between the gut and the brain.
According to Biesiekierski, people with IBS who believe they are gluten sensitive often respond in similar ways to gluten, wheat, and placebo challenges. “This suggests that how people anticipate and interpret gut sensations can strongly influence their symptoms,” she said.
Rather than being a clearly defined gluten driven condition, the review argues that NCGS sits within a broader spectrum of gut brain interaction disorders. For cyclists, this is an important distinction. Training load, fuelling strategies, stress, and race anxiety can all influence gut comfort, especially during long endurance rides or high intensity efforts.
Why this matters for cyclists
Gluten avoidance has become common in endurance sport, even among athletes without a medical diagnosis. Removing wheat-based foods can sometimes reduce symptoms, but it can also complicate fuelling. Bread, pasta, and cereals are convenient carbohydrate sources that support training volume and recovery. Cutting them out unnecessarily can increase the risk of under fuelling, particularly during demanding training periods.
Rethinking gluten messaging
The review also questions how gluten has been portrayed in public health messaging and food marketing. The rapid growth of the gluten free market has reinforced the idea that gluten is inherently harmful, despite limited evidence for most people.
“We would like to see public health messaging shift away from the narrative that gluten is inherently harmful, as this research shows that this often isn’t the case,” Biesiekierski said. She added that successful management should combine dietary adjustments with psychological support, while maintaining nutritional adequacy.
Practical takeaways for cyclists
- Feeling better after cutting out gluten does not automatically mean gluten was the problem. Reduced FODMAP intake or simpler food choices may explain the improvement.
- Long term gluten avoidance without a diagnosis can make it harder to meet carbohydrate needs for training and recovery.
- Persistent gut symptoms are best addressed with professional guidance, ideally from a dietitian familiar with endurance sport.
- Stress, expectations, and race nerves can amplify gut symptoms just as much as food choices.
