Gluten intolerance versus celiac disease
04/14/10 10:27 AM
Loc: Seattle, WA
April 8, 2010
Can You Be Intolerant to Foods Like Pasta?
By THE NEW YORK TIMES
Hundreds of readers had comments and questions for the New York Times Consults blog when the topic turned to celiac disease, an often overlooked digestive disorder that causes a range of problems, from infertility and anemia to digestive upset, when susceptible people eat gluten-rich foods like bread or pasta containing wheat, barley or rye.
Here, Dr. Sheila Crowe, a professor in the division of gastroenterology and hepatology in the department of medicine at the University of Virginia, responds to readers who asked whether you can be intolerant to gluten, the way some people might be intolerant to milk, without having full-blown celiac disease.
Intolerant to Gluten Without Having Celiac Disease?
What is your take on non-celiac gluten intolerance? There are some medical professionals who say that without the definitive markers of celiac disease (blunt villi, positive blood work), there is no reason to ever change to a gluten-free diet.
Could it be that the markers only become evident after a certain degree of damage and ill heath has been attained, and that celiac is really part of a spectrum of disease relating to the body's reaction to gluten? Thank you.
Can Dr. Crowe address briefly gluten intolerance? Although the symptoms are not as severe as those that celiacs experience, they are serious.
Does intolerance lead inevitably to celiac disease, and does the intolerance ever disappear over time, with healing? Many thanks.
Dr. Sheila Crowe responds:
Your comments and queries introduce a very important and somewhat controversial topic: gluten sensitivity, sometimes referred to as gluten intolerance. In fact, as testimony to how difficult it is to discuss the issue of gluten sensitivity, my co-author Ian Blumer and I decided not to include this topic in our recently published book "Celiac Disease for Dummies" (John Wiley and Sons, Canada). Relatively little high quality research has been conducted on the topic, and much more needs to be learned.
To start, even trying to define gluten sensitivity is difficult. Some experts reserve this term for cases in which symptoms of celiac disease are present but the intestinal biopsy remains normal. This definition separates celiac disease from gluten sensitivity based on the biopsy results. Other experts use the term gluten sensitivity to take into account the various gluten-dependent symptoms that can occur outside the digestive tract, even in patients with apparently normal intestinal biopsies.
Another view of gluten sensitivity encompasses a spectrum of conditions that range from classical celiac disease, with its intestinal abnormalities, to a syndrome in which avoidance of gluten in the diet leads to resolution of symptoms that resemble those of irritable bowel syndrome.
Between these extremes are individuals who have abnormal immune system (antibody) responses to gluten but who do not have abnormal intestinal findings on biopsies. (See my earlier post, "Confirming a Diagnosis of Celiac Disease," for more on antibody findings.) By this definition of gluten sensitivity, as long as someone has abnormal biopsies or antibody tests, or clinical symptoms that respond to excluding gluten from the diet, one can consider the disorder as a case of gluten sensitivity. Most specialists, however, exclude those with celiac disease — that is, those who have intestinal biopsy abnormalities — from the rest of the gluten-sensitive patients.
It is unknown how gluten causes symptoms in some of the gluten sensitive syndromes other than celiac disease. Most cases do not involve abnormal T-cell responses, as in celiac disease. Damage to neurological tissue may be because of other types of immune responses to gluten, and some scientists have postulated that the components of gluten may be toxic for some. Gluten has also been thought to cause a condition known as "leaky gut." These putative mechanisms, however, are only theories without solid scientific backing at this time.
To add confusion to an already complex problem, studies show that some gluten-sensitive patients who do not have abnormal biopsies have abnormal celiac disease antibodies, while others do not. Very often, the antibody type that is abnormal is the antigliadin antibody, particularly the IgG class of antibody, while the TTG antibody is often negative or normal. (Again, see my earlier post, "Confirming a Diagnosis of Celiac Disease.")
Genetic testing, which I discussed previously in "Genetic Testing for Celiac Disease," is also variable in patients with gluten sensitivity. Some individuals who are gluten sensitive with normal biopsies have the H.L.A. DQ2 or DQ8 genes that place them at risk of celiac disease, while others do not have these genes. These findings further suggest that being gluten sensitive is not one condition but most likely several different disorders that probably have different long-term outcomes and that may respond to different kinds of treatments.
Celiac Disease or Gluten Intolerance?
I would like to know how the diagnosis is made between having celiac disease and just being "intolerant" to gluten. Intolerant is the diagnosis my friend got, so she eats low doses. Further, can you ever "recover" to the point of being able to eat some gluten, i.e., just being "intolerant"?
Is there evidence for a "mild gluten intolerance," similar to mild lactose intolerance?
I was trained as a dietitian many years ago, and like other health care professionals, I was taught that celiac disease was a severe reaction/intolerance to any small amount of gluten. I now realize that I have celiac. I've done an elimination diet, and my symptoms — bloating and mild cramping — receded. I do not have more extreme symptoms, like diarrhea, vomiting, eczema, anemia, etc. Occasionally, I can eat a small amount of wheat without symptoms. But I can't figure out why.
There is also a rumor that "older varieties of wheat" do not cause symptoms. Has anyone tested/studied this assertion?
Is it possible to be wheat or gluten intolerant, but not have celiac disease?
After having the stomach biopsy, my daughter tested negative for celiac, but she feels better if she doesn't eat wheat. If she is wheat/gluten "intolerant," can this cause organ damage, etc., in the same way as celiac disease?
Should she be as careful as someone who has tested positive for celiac? Many thanks.
Dr. Sheila Crowe responds:
Holly, Rose and Jane all touch upon the important issue of how to best treat people with gluten sensitivity or gluten intolerance. Should they all be totally gluten-free or partly gluten-free? And does gluten actually harm them in the long run?
The bottom line is that no one really knows. Part of the problem is that it depends on what type of gluten sensitivity we are dealing with. Another concern is that there are no long-term, rigorously conducted scientific studies to tell us whether a specific diet or another treatment is helpful, harmful or makes no difference to gluten sensitive patients.
We know from many other studies that patients with digestive disorders like irritable bowel syndrome, or I.B.S., often feel better when taking placebos. This makes it difficult to show that a test drug or treatment, such as a gluten-free diet, has a real effect. My clinical experience suggests that quite a few patients with I.B.S. get better on a gluten-free diet, but this can be because of factors other than the harmful effects of gluten.
Gluten can be harder to digest than some other proteins in grains. Going gluten-free, as anyone who has tried this diet knows, eliminates lots of other factors from the diet. Most individuals on a gluten-free diet give up fast-food, prepared foods and packaged foods and instead eat more natural, fresh foods that are often prepared in the home. Feeling better may not necessarily be a result of excluding gluten in this setting. However, gluten may be causing problems in some people.
So how do we know who really needs to be gluten-free?
It depends on the type of patient. Some patients have symptoms of celiac disease but do not have an abnormal intestinal biopsy that is taken before starting a gluten-free diet (by definition, they are not categorized as having celiac disease). If blood tests show that such patients also have antibodies to tissue transglutaminase (TTG) or deamidated gliadin peptide (DGP), I would suggest that these individuals consider going on a truly gluten-free diet, since they are most likely on their way to celiac disease. The same advice could apply to those who have H.L.A. DQ2 or DQ8 genes without elevated antibodies, though in this case the recommendation is more ambiguous, since there are no immune abnormalities or intestinal damage.
Another scenario is the patient without an abnormal intestinal biopsy but who has neurological symptoms and an elevated antigliadin antibody (AGA). These individuals may not ever get celiac disease, but removing gluten from the diet may benefit their neurological problems.
For my patients without intestinal biopsy abnormalities, without celiac disease antibodies (including AGA IgG) and without H.L.A. celiac disease susceptibility (DQ2 or DQ8 genes), I advise a gluten-free diet only to control symptoms. Often these individuals can return to including gluten in their diets. This scenario likely applies to Holly's friend and to Rose. I would need more information, including antibody test results and genetic test results, to answer Jane's questions about her daughter.
I hope that, with time, we will understand gluten sensitivity better. It is likely that better defined subgroups of gluten sensitivity will emerge, which will allow us to make clearer recommendations for diagnosis and treatment.
Heather is the Administrator of the IBS Message Boards. She is the author of Eating for IBS and The First Year: IBS, and the CEO of Heather's Tummy Care. Join her IBS Newsletter. Meet Heather on Facebook!