Not everyone who avoids gluten has celiac disease or a wheat allergy and new research suggests that they’re far from alone.
A sweeping analysis published in Gut finds that about one in 10 people worldwide report symptoms such as bloating, fatigue or headaches after eating foods that contain gluten or wheat, even though they haven’t been diagnosed with either condition. The findings are based on 25 studies involving nearly 50,000 people from 16 countries.
Researchers call the condition non-celiac gluten/wheat sensitivity (NCGWS). Unlike celiac disease, which damages the small intestine, or wheat allergy, which triggers an immune reaction, NCGWS doesn’t have a clear biological marker or test. It’s diagnosed when people consistently feel better avoiding gluten and worse when they eat it again.
The new review found that symptoms of self-reported sensitivity varied widely but often included bloating, abdominal discomfort, pain, and fatigue. Four in 10 participants said they were following a gluten-free diet to manage those symptoms, often without medical guidance.
The researchers also found patterns in who reported gluten sensitivity. Women were more likely to report symptoms than men, and there were strong overlaps with conditions such as irritable bowel syndrome (IBS), anxiety, and depression.
“Self-reported non-coeliac gluten/wheat sensitivity affects approximately one in ten people worldwide, with a considerable geographical variation and strong association with female sex, psychological distress and irritable bowel syndrome,” the authors wrote.
The reported prevalence ranged from less than 1% in Chile to more than 20% in the United Kingdom and over 30% in Saudi Arabia. Researchers say those differences could reflect true regional variation or differences in how gluten sensitivity is defined and diagnosed.
Because the study relied on self-reported symptoms, the authors caution that the findings don’t prove a single cause. Instead, they say the symptoms may arise from a mix of factors involving digestion, gut bacteria, and brain–gut communication. They recommend recognizing gluten sensitivity as part of a broader category of gut–brain interaction disorders, which includes IBS, rather than treating it solely as a food intolerance.
The researchers concluded that more specific diagnostic criteria are needed to help doctors distinguish between gluten sensitivity, IBS and other functional gut disorders, and to avoid unnecessary dietary restriction.
The authors reported no specific grant or funding support for this research from any public, commercial or nonprofit agency.