I first came across the term “wheat sensitivity” in an editorial entitled, “Non-Celiac Wheat Sensitivity: Separating the Wheat from the Chat,” in the December 2012 issue of the American Journal of Gastroenterology. Thanks to a night of bad insomnia and a pretty interesting original research article by Carroccio, et al., in the same issue, I kept on reading…
Researchers out of Palermo, Sicily, state that “wheat sensitivity” is a both a new and real diagnosis. They reviewed the medical records of 267 patients diagnosed with both Irritable Bowel Syndrome (IBS) and “wheat sensitivity” during the 10-year period from 2001 thru 2011. All of their patients with wheat issues met the following criteria:
- Symptoms of irritable bowel syndrome
- Negative celiac antibody testing for TTG (tissue transglutaminase) and EMA (endomysial) antibodies
- Normal small intestinal biopsies (no villous blunting like that seen in celiac disease)
- Negative IgE (skin prick) testing for a wheat allergy
- Improvement in gastrointestinal symptoms on a wheat free diet by a double-blind placebo challenge
For the double-blind placebo wheat challenge the patients ate a regular diet, including 30 grams of wheat, daily for 2 to 4 weeks. 30 grams of wheat equals 1 slice of bread. They then had a 2-week elimination period, in which they stopped eating wheat, dairy, tomatoes, eggs, and chocolate, all of which are considered highly allergenic foods in Italy. After the elimination diet period, they were then given one of two pills everyday for 2 weeks. Pill “A” contained wheat and Pill “B” was a placebo sugar pill. Neither the research subjects, nor the researchers, knew which pill each subject was taking during the test period; this is why it is called a “double-blind” placebo study. There was a one week interim period in which subjects avoided all of the allergenic foods again, and then those who received pill “B” for the 1st two weeks were given “A” for the 2nd two week period and vice versa. The beauty of this type of crossover study is that each subject served as his or her own control.
If you’ve actually read this far, you may be wondering what the researchers found when they re-analyzed the 276 cases of wheat sensitivity….see below!
Compared to patients with Celiac Disease and IBS, those with “wheat sensitivity” have the following characteristics:
- Increased likelihood of having atopic diseases (i.e. eczema, hay fever, environmental allergies)
- Increased history of food allergies, especially during infancy
- Elevated numbers of eosinophils (white blood associated with allergic reactions) in both the small and large intestine
- Abnormally high anti-gliadin antibodies (a type of antibody against one of the gluten proteins) compared with those with IBS
- Higher rates of anemia and weight loss than seen in those patients with non-wheat sensitive IBS
The researchers were able to break down the 276 wheat sensitive individuals into 2 groups. Those in Group 1 (n=70) shared many characteristics with Celiac patients, including having the genes that predispose to Celiac Disease (HLA DQ2 and/or DQ8). They believe that these wheat sensitive patients with IBS are at risk for the later development of celiac disease. Those in Group 2 (n=206) were found to have multiple food intolerances, including having antibodies to cow’s milk proteins, despite not having IgE mediated food allergies on skin prick testing. This group was referred to as the multiple food sensitivity group.
I believe that the researchers have done a great job demonstrating that there are many people with IBS who may benefit from being wheat free. I wish that I had known this when I was diagnosed with IBS at age 19. I was advised to increase my consumption of healthy whole grains, which I did; unfortunately, most of my increased grain consumption was in the form of whole wheat!
Perhaps in the future gastroenterologists will be able to use the presence/absence of eosinophils in the small and large intestines to help guide nutritional recommendations for patients with IBS. I am especially interested in seeing what the future holds for learning about links between wheat and cow’s milk protein sensitivities. I work with newborn babies and it seems like the numbers of babies with cow’s milk protein allergies are skyrocketing. I hope to write more about this soon.