It’s funny how diseases get started. Some are pretty obvious: infectious bacteria, viruses, and mutations causing a myriad of cancers. But then, there are those epidemic “syndromes” that have a more questionable origin.
In the 60’s, allergies to petroleum products were all the rage. People moved out of homes—in which they had lived for decades—because they discovered that the walls or the carpets or the stuff in the bathroom cabinet caused them to itch or gave them heart palpitations, headaches, or a foggy mind, or even outright depression. A cottage industry, called “clinical ecology,” sprang up, mostly in the South. People traveled to Texas where they lived for weeks on end in rooms with stainless steel walls (no formaldehyde) to get a diagnosis or to just get relief from the modern world. A colleague of mind, a clinician and a scientist, was so convinced he suffered from this syndrome that he moved out of his home and into a shed that presumably was formaldehyde-free. He even conducted a small clinical trial at the behest of the Society of Clinical Ecologists and found that…the thing didn’t exist. Yes, the effects of formaldehyde on the airways are real. But foggy mind? depression? No. Further investigations uncovered some “inaccuracies” in the medical records, and to add insult to injury, formaldehyde was detected in those stainless steel “clean” rooms.
I was a freshly minted physician at the time, and this episode taught me an invaluable lesson: When a syndrome enjoys sudden popularity and is so vague as to defy a straightforward diagnosis, handle with extreme skepticism.
Now let’s move on to this era’s popular syndrome: Gluten sensitivity or, more accurately, non-celiac gluten sensitivity. But first, let’s distinguish between gluten sensitivity and the well-characterized disorder, celiac disease.
What is celiac disease?
Celiac disease is an autoimmune disease that is triggered by gluten in the diet and results in the destruction of the villi (small projections of the small intestine that carry digestive enzymes of their surfaces). The consequences are malabsorption, abdominal pain, bloating, vomiting, diarrhea, weight loss, and fatigue. Symptoms can vary from mild to severe. The definitive diagnosis is made via a specific blood test and intestinal biopsy.
The disease was initially thought to be extremely rare. Ten years ago, it was estimated to occur in 1 in 10,000 people. But due to increased awareness among physicians, the prevalence of the disease has been recently shown to be 1 in 100. However, because of the wide variation in symptoms, only 5% are aware that they have it.
What is non-celiac gluten sensitivity?
Awareness of non-celiac gluten sensitivity (NCGS) got its start in the 70’s and 80’s when a few small and poorly designed nutritional and immunological studies were published in third-line publications. But in 2011, a real study—double-blind, randomized, and placebo-controlled—was published by Peter Gibson and his colleagues at Monash University in Australia. They studied 34 people with irritable bowel syndrome who did not have celiac disease, but complained of bad reactions to wheat, a gluten-rich grain. The salient finding was that of 19 patients in the gluten group, 13 (68%) reported that symptoms were not adequately controlled by a gluten-free diet compared with 6 of 15 (40%) on placebo. Pretty damning. Charitably, the authors concluded that
“Non-celiac gluten intolerance” may exist, but no clues to the mechanism were elucidated.”
Gibson, a gastroenterologist, did not just stop there. The fact that gluten did not prove to be the culprit did not mean that the symptoms were not be caused by something else in the food. In 2013, he and his colleagues reported on a second study. Again, they tested 34 people with irritable bowel disease who did not have celiac disease but reported sensitivity to gluten. Initially, all of the patients received a diet low in FODMAPS for 2 weeks. FODMAPS are a group of fermentable carbohydrates that some people have difficulty digesting because of a deficiency of one or more enzymes. Although everyone continued on the low FODMAPS diet, they were randomly assigned to one of three groups: high-gluten (16 g gluten/d), low-gluten (2 g gluten/d and 14 g whey protein/d), or control (16 g whey protein/d) diets for an additional week. This was followed by a washout period of at least 2 weeks. The authors concluded,
“In contrast to our first study… we could find absolutely no specific response to gluten”
Halleluja, scientific integrity at its best.
One of the problems of the two papers was that the NCGS was “self-reported”, namely, the patients made the diagnosis. Another problem was the small number of subjects. Not to let that go unexamined, Gibson conducted a larger study to check if patients who believed they suffered from NCGS indeed had the disease. They recruited 147 patients who completed a questionnaire and then tested with a similar protocol to the previous study. The results largely confirmed the previous findings.
There most probably exists a cohort of people who have an undiagnosed celiac disease. The syndrome runs a gamut of symptoms, from severe abdominal pain and chronic diarrhea to headaches and fatigue, but no GI symptoms at all. As mentioned, it is estimated that more than 90% of the people who suffer from celiac don’t know it. Other people may suffer from insufficiency of FODMAP digestion, manifesting in bloating and diarrhea.
But these two diseases don’t account for epidemic proportions of people who self-diagnose as NCGS. Thirty percent of the U.S. population attribute a variety of symptoms to gluten. Do 90 million people walk around with bellyaches, bloating, diarrhea, headaches, and fatigue? If so, Donald Trump may be right: Our country is in the toilet. But just like his portrayal of the U.S., this is simply not credible. If you suffer from these GI symptoms, by all means, see your doctor and get a proper blood test and a biopsy, to rule out celiac disease. I would venture a guess, though, that most people will turn out to suffer from “epidemicitis” (that’s a made-up word so don’t bother to Google it), and just like the “hypoglycemic epidemic” of a few years ago, this one will pass as well.