Celiac Disease on the Rise

According to a new report in Gastroenterology (July 09), Celiac Disease is now 4 times more common in the US than it was during the 1950’s. The disease results from an intolerance to the protein gluten, found in wheat, barley, and rye.  When celiac patients consume gluten, they suffer an inflammatory reaction within the small intestine that can lead to a host of manifestations, including abdominal pain, diarrhea, weight loss, anemia, infertility, malnutrition, and premature osteoporosis.  It can develop at any age and is frequently misdiagnosed or undiagnosed because of its non-specific symptoms.  Based on this new evaluation, about 1 in 100 people have it and many are not aware.  Anyone with chronic gastrointestinal complaints or any of the features listed above, should be screened for this disease.  A simple blood test can determine the diagnosis in most cases.  Treatment entails lifelong adherence to a gluten-free diet.  The “silver lining” for folks diagnosed with Celiac disease is that it largely and forever commits them to a wholesome, natural, “real foods” diet, as most processed, man-made foods contain gluten.

From Dr. Ann Kulze Newsletter

Okay, CAS thinkers, what are some theories that would explain the numbers?

  • Tiltmom

    Just read a couple of pieces on this. One recent one in NYT speculated:

    “Doctors don’t know why celiac is on the rise. It may be due to changes in the way wheat is grown and processed, or the ubiquity of gluten in medications and processed foods.”

    Sci Am did an interesting piece on celiac this month but doesn’t speculate on why there is a rise.

    I hate offering conjecture without a cite, but I know I read somewhere that we changed the way we’re breeding wheat [since the early 80s?] to have a higher protein content, hence a higher gluten content. That’s in conjunction with the NYT speculation above. If I find the article, I’ll update this comment.

  • danielhorowitz

    Regarding this study in particular, it’s possible that the Air Force group received more vitamin D and performed more exercise, which we believe to be protective against auto immune diseases. Later in life, neither of these were necessarily the case.

    Perhaps more likely, we eat too much gluten and after some time our body starts to reject it.

  • kevindick

    “frequently misdiagnosed or undiagnosed “. I think the null hypothesis should be that it is not in fact more prevalent, we just diagnose it more often. Presumably, this study did something to account for that, but with no link, I can’t check. It’s also really hard to do in practice.

  • Tiltmom

    No, Kevin, it’s actually more prevalent, not more diagnosed:

    In the Mayo Clinic study, stored blood samples collected from healthy male army recruits between 1948 and 1954 were tested for the presence of a celiac-specific antibody.

    The Mayo researchers also tested blood samples collected just a few years ago from men whose ages were either similar to the recruits at the time the samples were taken or at the time of the study.

    They found that:

    The samples from the contemporary group of young people were 4.5 times more likely to have the celiac antibody than the samples drawn in the 1950s.

    The contemporary samples taken from older men whose ages matched the current ages of the recruits were four times as likely to have the antibody.

    During 45 years of follow-up, undiagnosed celiac disease was associated with a fourfold increased risk of death.

  • Tiltmom

    Here’s a more thorough link, though it doesn’t link to the actual Mayo study:

    http://bit.ly/74OKu

    The Vitamin D aspect is being looked at, too:

    http://bit.ly/jDsMa

    • kevindick

      I’d like to see the whole study. I can imagine several ways that using an antibody proxy after 50 years might not be indicative. So this isn’t really a true measure of the disease prevalence.

      What would be interesting is if they could show an increase in true disease prevalence over 10 or 20 years. Then you can fit the curves and be more confident that the antibody proxy is accurate 50 years back.

  • danielhorowitz

    @Kevin – This was my initial reaction as well, but it does not appear to be the case.

    Here is a link to the study. http://www.celiac.org/downloads/Increase%20Prevalence_%20Tapia%20and%20Murray%202009.pdf

    • kevindick

      I didn’t see much treatment of whether the antibody test would be valid on blood samples stored for 50 years. They asserted that immunoglobulin is stable, but I’d like to see a more sophisticated argument.

  • danielhorowitz

    Although I offered it up myself, the global distribution of Celiac disease does not give much weight to a strong Vitamin D connection.

  • rafefurst

    On twitter, Dr. Ann and I started this sub-thread, which I’m moving here now…

    Ann: At this point scientist have no idea, however it is clear based on studies that the uptick is clearly environmentally driven.

    Rafe:: how can u b be sure genetic drift is not at play in Celiac (& autism & other diseases…)? http://is.gd/2mUxb

    Ann:: With your understanding of GD, do U think GD could explain a 4 fold increase over 60 years?

    While it seems unlikely that that the fourfold increase could be explained by genetic drift (or even selective pressure) in under three generations, it is possible due to non-linear threshold effects. In other words, the predisposition towards celiac drifts (or is co-selected for) over many generations and then manifests itself due to a drastic environmental change, such as near total degeneration of the food supply in the last 60 years.

  • There are other factors. Due to the increasing knowledge of the medical world more diseases are becoming chronic, and people with a chronic disease can lead a more normal life (within the boundaries they have). However more people are likely to have children, with a genetic mutation thereby increasing the risk of developing the disease. Combining an increasing prevalence of genetic disposition of a disease, with increased diagnostic markers and more specific and sensitive (early) testing could account for a increase in the general population. (i guess)

    • rafefurst

      Yes, I agree this could be a factor. For any phenotypic change in a population, selective forces can either work towards it (i.e. higher “fitness”), against it, or be neutral. Genetic drift refers to neutral pressure situations.

      In the absence of other evidence, one would suspect a celiac condition would either be neutral to overall fitness, or perhaps slightly negative as in the scenario you pose, but not negative enough to overcome massive environmental shifts that trigger manifestation of chronic diseases.

      I will point out that there is a third “selective” scenario too, which is that the predisposition toward celiac coincidentally co-varies with a trait that is being positively selected for in the population (who knows, maybe celiacs are more fertile :-)

      More confounding still — and this is the part that most life-science folks don’t understand — is that evolution is multi-scale and in particular culture and biology coevolve. But culture can evolve much faster than biology and so if you look at the system as a whole and admit to the reality that celiac is a condition that involved both biological and cultural factors (i.e. whether you eat a lot of wheat is a culture thing), then the evolutionary pace of the overall system doesn’t strain credulity at all.

      One of the hottest topics in systems biology and evolutionary development is known as facilitated variation (or sometimes the Baldwin Effect), which essentially marries genetics adaptation with non-genetic adaptation (e.g. cultural evolution).

  • Why are we surprised about the rise of celiac diagnoses? Yes longer storage rates of grains with higher gluten content plays a role as does the fact that gluten contains a small amount of opioid exorphins (leading to, you guessed it, “comfort food addiction)…
    But more importantly, we know that HLA-DQ2, DQ8 and other genes are present in over 40% North-American individuals, many of UK northern European or mediterranean backgrounds. We also know that these genes surface in close to 90% of South-American and indigenous peoples… and, many with other (inaccurate) diagnoses and even diabetes in fact are gluten-intolerant due to the presence of the HLA-DQ2, DQ8 or other genes.
    For this reason, the increased consumtion of processed foods worldwide directly relates to increased rates of gluten-intolerance and celiac disease.

    • rafefurst

      Thank you for the stats and insights!

  • Daniel Horowitz

    “Celiac patients have almost twice the normal risk of cancer, and one-third of them suffer from another autoimmune disease, like Type 1 diabetes, lupus, or multiple sclerosis.”

    http://www.slate.com/id/2223745/pagenum/all/

  • danielhorowitz

    Good article from the current Columbia (University) magazine about Celiac.

    http://www.columbia.edu/cu/alumni/Magazine/Winter2009-10/feature3.html

  • Celiac disease has been making people suffer ever since but people tend to ignore it or just consider it as something like a fever that can be cured easily. But what they do not know is that it concerns a lot more and when the symptoms start to show, it gets more difficult.

  • I don’t know but I think celiac disease is caused by our own diet as well. Well, it could be sometimes passed on through the genes. I, myself, has gluten intolerance and also my daughter so that is why I have that perception about the condition.