COMMON FOOD INTOLERANCES IN IBD

Those with inflammatory bowel disease (IBD) have twice as many food intolerances as healthy people. So it's logical that doctors are looking to find ways to identify those intolerances. These are different than food allergies, which are immediate reactions that often are like environmental allergies (to grass and trees, for example). Food allergies usually have positive skin tests or blood tests with high IgE levels to certain foods <<link N4K food allergies>> while food intolerances don't show up on those tests.

Identifying Food Intolerance

Can we identify food intolerances somehow?  And do these food intolerances cause any of the symptoms or injury in IBD? To understand that, a number of studies are being done. They suggest that blood tests for IgG (also known as gamma-globulin) can detect food intolerances – sometimes when patients don't even have any symptoms.

The Most Common Food Intolerances

A recent study from Tianjin, China (L Jian and others, Inflammatory Bowel Dis, 2018, pages 1918-25) showed that in 97 patients with ulcerative colitis, certain foods were more likely to create a IgG response, some with high IgG levels (the most severe were graded as +++):

                           Patients with levels          Response for most         

Egg                                         60%                                       +++

Wheat                                  38                                        + /+++      

Milk                                       32                                          +++       

Corn                                      30                                              +         

Tomato                                26                                           +/+++

Crab                                       23                                              +

Rice                                        18                                           +++

Soy                                         16                                           +++

Other foods also created an IgG response but at lower levels: cod, shrimp, mushroom and beef, with no response to chicken or pork. In a similar study in Crohn's disease, beef and pork were more common (V Gunasekeera and others, Digestive Dis Science, 2016, pages 1148-57).

Food Intolerances Guiding Treatment

The researchers had half the patients eliminate the foods they reacted to, whether or not they had symptoms from those foods and had good results compared to the other half who were asked to remain on a healthy diet. Good results were also found when IgG was used to guide diet change in the study with Crohn's disease. Certainly, more research is needed–and fortunately, that is being done.

Another option is to keep a symptom diary <<link>> to find food triggers and intolerances. Either way, you should discuss your findings with your doctor, because eliminating foods can cause nutritional deficiencies.