Written by Joyce Smith, BS. This study found no correlation between dietary gluten intake and the risk for incidence Crohn’s disease or ulcerative colitis among women and men without celiac disease.
Crohn’s disease and ulcerative colitis, collectively known as inflammatory bowel disease (IBD), are chronic inflammatory disorders of the gastrointestinal tract 1. Although the etiopathogenesis of IBD is not well known, diet can play a role through its influence on the composition of the gut microbiome and the maintenance of a tight mucosal barrier junction 2. It also plays a role in the regulation of mucosal inflammation 2. The western diet, in particular, has been linked to increased mucosal inflammation 2. While genome-wide association studies have identified a role for genetic risk factors, environmental factors are playing a much larger role are 3,4. Gluten, a protein in wheat, barley, and rye, is a celiac disease trigger and has popularized the gluten free diet even for those who don’t have celiac disease. 5 People with IBD have an increased risk for celiac disease 6 and non-celiac gluten sensitivity 7.
The need to examine the relationship between dietary gluten and risk of IBD in adults without celiac disease prompted the following study 8 that examines the relationship between dietary gluten intake and risk of IBD. The study involved participants from three large prospective US cohorts of men and women. Included were 121,700 female nurses, ages 30-55 years, enrolled in the Nurses’ Health Study (NHS)in 1976; 116,429 female nurses, ages 25-42 years, enrolled in the NHSII study in1989; and 51,529 US male physicians, ages 40-75 years, enrolled in the Health Professionals Follow-Up Study (HPFS) in 1986. Appropriate baseline and biannual semi-quantitative food frequency questionnaires (SFFQ) as well as questions on lifestyle factors, anthropometric measurements, and medical information were completed by all participants. Follow up rates were high: 90% (NHS), 85% (NHS11), and 93% (HPFS) cohorts.
Through the end of follow up, researchers found 337 CD cases and 447 UC cases over a total of 5,115,265 person-years; however, dietary gluten was not linked to a risk for incident CD or UC. Compared to participants in the lowest quintile of gluten intake (baseline mean = 3.1 grams/day), individuals in the highest quintile of energy-adjusted gluten intake (baseline mean = 8.5 grams/day) were not at increased risk for CD (adjusted HR = 1.16; 95% CI, 0.82-1.64 Ptrend= 0.41) or UC (adjusted HR = 1.04; 95% CI, 0.75-1.44; Ptrend = 0.64). These values did not change after adjusting for primary sources of gluten intake, nor did baseline age, BMI or smoking status modify the correlation between gluten intake and risk for CD or UC.
Limitations include error in measuring gluten intake, an inability to explore the relationship between a gluten-free diet and IBD risk or to assess gluten derived from barley and rye. Baseline age in the study was higher than actual age onset of IBD in participants. There was also no generalizability (participants were Caucasian health care professionals) and lastly, there was possible residual confounding due to potential antibiotic use.
Researchers conclude that long-term intake of gluten did not increase IBD risk in US adults, even in those with an IBD family history. Gluten from refined grains (but not whole grains that provide health benefits) may be associated with an increased risk of CD in older adults and should be confirmed in future studies. The team also recommend that people who do not have celiac disease should not avoid gluten as a precautionary measure to prevent IBD.
Source: Lopes, Emily W., Benjamin Lebwohl, Kristin E. Burke, Kerry L. Ivey, Ashwin N. Ananthakrishnan, Paul Lochhead, James M. Richter et al. “DIETARY GLUTEN INTAKE IS NOT ASSOCIATED WITH RISK OF INFLAMMATORY BOWEL DISEASE IN US ADULTS WITHOUT CELIAC DISEASE.” Clinical Gastroenterology and Hepatology (2021).
© 2021 by the AGA Institute
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Posted April 27, 2021.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
References:
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- Khalili H, Chan SSM, Lochhead P, Ananthakrishnan AN, Hart AR, Chan AT. The role of diet in the aetiopathogenesis of inflammatory bowel disease. Nature reviews Gastroenterology & hepatology. 2018;15(9):525-535.
- Jostins L, Ripke S, Weersma RK, et al. Host-microbe interactions have shaped the genetic architecture of inflammatory bowel disease. Nature. 2012;491(7422):119-124.
- Liu JZ, van Sommeren S, Huang H, et al. Association analyses identify 38 susceptibility loci for inflammatory bowel disease and highlight shared genetic risk across populations. Nat Genet. 2015;47(9):979-986.
- Kim HS, Patel KG, Orosz E, et al. Time Trends in the Prevalence of Celiac Disease and Gluten-Free Diet in the US Population: Results From the National Health and Nutrition Examination Surveys 2009-2014. JAMA Intern Med. 2016;176(11):1716-1717.
- Shah A, Walker M, Burger D, et al. Link Between Celiac Disease and Inflammatory Bowel Disease. J Clin Gastroenterol. 2019;53(7):514-522.
- Limketkai BN, Sepulveda R, Hing T, et al. Prevalence and factors associated with gluten sensitivity in inflammatory bowel disease. Scand J Gastroenterol. 2018;53(2):147-151.
- Lopes EW, Lebwohl B, Burke KE, et al. Dietary Gluten Intake is Not Associated with Risk of Inflammatory Bowel Disease in U.S. Adults without Celiac Disease. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2021.
