After a formal evaluation to rule out celiac disease, those who suspect they might have gluten sensitivity should first try improving their diet and then have other causes excluded before going on a gluten-free diet, since as many as 1 in 3 people who avoid gluten for symptom control end up having a different disease altogether.
How to Diagnose Gluten Intolerance
Symptoms of gluten sensitivity include irritable bowel type symptoms such as bloating, abdominal pain, and changes in bowel habits, as well as systemic manifestations such as brain fog, headache, fatigue, depression, joint and muscle aches, numbness in the extremities, a skin rash or anemia. If those who suspect they might be gluten sensitive should not go on a gluten-free diet, what should they do?
The first thing is a formal evaluation for celiac disease, which currently involves blood tests and a small intestinal biopsy. If that’s positive then one goes on a gluten-free diet, but if it’s negative we should try a healthier diet, more fruits and vegetables, more whole grains and beans while avoiding processed junk.
In the past, a gluten-free diet had many benefits over the traditional American diet because it required increasing fruit and vegetable intake, so no wonder people felt better eating gluten free—no more deep-fried twinkies, couldn’t eat in fast food restaurants. Now, though, there is just as much gluten-free junk out there.
It’s like the vegan doughnut phenomenon. A few decades ago vegans were forced to eat healthy, eat actual vegetables. Now they can eat their cheesy puffs, while waiting for their candy-coated chocolate marshmallows to deep-fry in vegan bacon grease.
If a healthy diet doesn’t help, then I might add another step here, and that is try to rule out other causes of chronic GI distress. When researchers study PWAWGS — that’s what they’re called in the literature, people who avoid wheat and/or gluten. In a study of 84 PWAWGS, about a third didn’t appear to have have gluten sensitivity at all, but instead had an overgrowth of bacteria in their small intestine, were fructose or lactose intolerant, or had a neuromuscular disorder like gastroparesis or pelvic floor dysfunction. When those are all ruled out as well, then I’d suggest people suffering from chronic suspicious symptoms should try a gluten-free diet, and if symptoms improve, stick with it, though maybe rechallenging with gluten periodically.
Unlike celiac disease, a gluten-free diet is begun not to prevent serious complications from an autoimmune reaction, but just to resolve gluten sensitivity symptoms to try to improve patients’ quality of life. However, a gluten-free diet itself can reduce quality of life, so it’s a matter of trying to continually strike the balance. For example, gluten-free foods can be expensive, averaging about triple the cost and so most people would benefit from instead buying an extra bunch of kale or blueberries instead.
No current data suggest that that general population should maintain a gluten-free lifestyle, but for those with a celiac disease, wheat allergy, or sensitivity diagnosis, gluten-free diets can be a life-saver.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
To help out on the site please email volunteer@nutritionfacts.org.
- A. R. Lee, D. L. Ng, J. Zivin, P. H. R. Green. Economic burden of a gluten-free diet. Journal of human Nutrition and Dietetics 2007 20(5):423 – 430.
- P. Nijeboer, H. J. Bontkes, C. J. J. Mulder, G. Bouma. Non-celiac Gluten Sensitivity. Is it in the Gluten or the Grain? J Gastrointestin Liver Dis 2013 22(4):435 – 440.
- A. Tavakkoli, S. K. Lewis, C. A. Tennyson, B. Lebwohl, P. H. R. Green. Characteristics of patients who avoid wheat and/or gluten in the absence of Celiac disease. Dig. Dis. Sci. 2014 59(6):1255 – 1261.
- M. Pietzak. Celiac disease, wheat allergy, and gluten sensitivity: When gluten free is not a fad. JPEN J Parenter Enteral Nutr 2012 36(1 - Suppl):68S - 75S.
- P. Mansueto, A. Seidita, A. D'Alcamo, A. Carroccio. Non-celiac gluten sensitivity: Literature review. J Am Coll Nutr 2014 33(1):39 – 54.
- J. R. Biesiekierski, E. D. Newnham, S. J. Shepherd, J. G. Muir, P. R. Gibson. Characterization of Adults With a Self-Diagnosis of Nonceliac Gluten Sensitivity. Nutr Clin Pract 2014 29(4):504 – 509.
- L. Elli. Where's the evidence for gluten sensitivity? BMJ 2012 345:e7360.
- C. Cross. Gluten-free industry is healthy, but is the food? CMAJ 2013 185(13):E610.
- P. Nijeboer, H. J. Bontkes, C. J. J. Mulder, G. Bouma. Non-celiac Gluten Sensitivity. Is it in the Gluten or the Grain? J Gastrointestin Liver Dis 2013 22(4):435 – 440.
- D. F. McCarter. Non-Celiac Gluten Sensitivity: Important diagnosis or dietary fad? January 15, 2014 Volume 89, Number 2.
- I. Aziz, D. S. Sanders. Patients who avoid wheat and gluten: is that health or lifestyle? Dig Dis Sci. 2014 Jun;59(6):1080-2.
Images thanks to Luke Gattuso via Flickr.
Symptoms of gluten sensitivity include irritable bowel type symptoms such as bloating, abdominal pain, and changes in bowel habits, as well as systemic manifestations such as brain fog, headache, fatigue, depression, joint and muscle aches, numbness in the extremities, a skin rash or anemia. If those who suspect they might be gluten sensitive should not go on a gluten-free diet, what should they do?
The first thing is a formal evaluation for celiac disease, which currently involves blood tests and a small intestinal biopsy. If that’s positive then one goes on a gluten-free diet, but if it’s negative we should try a healthier diet, more fruits and vegetables, more whole grains and beans while avoiding processed junk.
In the past, a gluten-free diet had many benefits over the traditional American diet because it required increasing fruit and vegetable intake, so no wonder people felt better eating gluten free—no more deep-fried twinkies, couldn’t eat in fast food restaurants. Now, though, there is just as much gluten-free junk out there.
It’s like the vegan doughnut phenomenon. A few decades ago vegans were forced to eat healthy, eat actual vegetables. Now they can eat their cheesy puffs, while waiting for their candy-coated chocolate marshmallows to deep-fry in vegan bacon grease.
If a healthy diet doesn’t help, then I might add another step here, and that is try to rule out other causes of chronic GI distress. When researchers study PWAWGS — that’s what they’re called in the literature, people who avoid wheat and/or gluten. In a study of 84 PWAWGS, about a third didn’t appear to have have gluten sensitivity at all, but instead had an overgrowth of bacteria in their small intestine, were fructose or lactose intolerant, or had a neuromuscular disorder like gastroparesis or pelvic floor dysfunction. When those are all ruled out as well, then I’d suggest people suffering from chronic suspicious symptoms should try a gluten-free diet, and if symptoms improve, stick with it, though maybe rechallenging with gluten periodically.
Unlike celiac disease, a gluten-free diet is begun not to prevent serious complications from an autoimmune reaction, but just to resolve gluten sensitivity symptoms to try to improve patients’ quality of life. However, a gluten-free diet itself can reduce quality of life, so it’s a matter of trying to continually strike the balance. For example, gluten-free foods can be expensive, averaging about triple the cost and so most people would benefit from instead buying an extra bunch of kale or blueberries instead.
No current data suggest that that general population should maintain a gluten-free lifestyle, but for those with a celiac disease, wheat allergy, or sensitivity diagnosis, gluten-free diets can be a life-saver.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
To help out on the site please email volunteer@nutritionfacts.org.
- A. R. Lee, D. L. Ng, J. Zivin, P. H. R. Green. Economic burden of a gluten-free diet. Journal of human Nutrition and Dietetics 2007 20(5):423 – 430.
- P. Nijeboer, H. J. Bontkes, C. J. J. Mulder, G. Bouma. Non-celiac Gluten Sensitivity. Is it in the Gluten or the Grain? J Gastrointestin Liver Dis 2013 22(4):435 – 440.
- A. Tavakkoli, S. K. Lewis, C. A. Tennyson, B. Lebwohl, P. H. R. Green. Characteristics of patients who avoid wheat and/or gluten in the absence of Celiac disease. Dig. Dis. Sci. 2014 59(6):1255 – 1261.
- M. Pietzak. Celiac disease, wheat allergy, and gluten sensitivity: When gluten free is not a fad. JPEN J Parenter Enteral Nutr 2012 36(1 - Suppl):68S - 75S.
- P. Mansueto, A. Seidita, A. D'Alcamo, A. Carroccio. Non-celiac gluten sensitivity: Literature review. J Am Coll Nutr 2014 33(1):39 – 54.
- J. R. Biesiekierski, E. D. Newnham, S. J. Shepherd, J. G. Muir, P. R. Gibson. Characterization of Adults With a Self-Diagnosis of Nonceliac Gluten Sensitivity. Nutr Clin Pract 2014 29(4):504 – 509.
- L. Elli. Where's the evidence for gluten sensitivity? BMJ 2012 345:e7360.
- C. Cross. Gluten-free industry is healthy, but is the food? CMAJ 2013 185(13):E610.
- P. Nijeboer, H. J. Bontkes, C. J. J. Mulder, G. Bouma. Non-celiac Gluten Sensitivity. Is it in the Gluten or the Grain? J Gastrointestin Liver Dis 2013 22(4):435 – 440.
- D. F. McCarter. Non-Celiac Gluten Sensitivity: Important diagnosis or dietary fad? January 15, 2014 Volume 89, Number 2.
- I. Aziz, D. S. Sanders. Patients who avoid wheat and gluten: is that health or lifestyle? Dig Dis Sci. 2014 Jun;59(6):1080-2.
Images thanks to Luke Gattuso via Flickr.
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How to Diagnose Gluten Intolerance
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Content URLDoctor's Note
If you missed the first two videos of my 3 part series on the latest in gluten, check out Is Gluten Sensitivity Real? and Gluten-Free Diets: Separating the Wheat from the Chat. I’m curious how this has all been received. I hope it helped clear things up.
Please let me know what you thought of my coverage of the best available science I found. If there are any pieces you think I missed or got wrong, please let me know so I can correct them!
And check out my 2022 video, The Potential Harm in Unnecessary Gluten-Free Diets.
Some food strategies that may help with irritable bowel symptoms are covered in a few of my previous videos, such as Kiwifruit for Irritable Bowel Syndrome and Cayenne Pepper for Irritable Bowel Syndrome and Chronic Indigestion.
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