On Nutrition

Gluten-free diets remain popular among those who suspect they can’t tolerate gluten — a protein found in wheat, rye and barley — and even those who simply assume a gluten-free diet is healthier. While there are many reasons not avoid gluten unless you have to, I want to discuss why trying to self-diagnose a possible “gluten intolerance” is a bad idea.

Gluten intolerance is a nonspecific term that encompasses celiac disease and non-celiac gluten/wheat sensitivity. While these conditions have symptoms in common, there’s one critical difference. Celiac disease — an autoimmune disease in which the body’s immune system inappropriately reacts to gluten — causes real harm. Out of 100 people, one or two have celiac disease. They were genetically susceptible and experienced something — such as an infection or illness — that triggered their immune system to start responding inappropriately to gluten. As a result, the wall of the small intestine becomes damaged,  making it difficult to absorb several vitamins and minerals, including vitamin B12, folic acid, iron and calcium. This affects the entire body.

I’ve had many people tell me that they have a problem with gluten but “know” they don’t have celiac disease because their symptoms aren’t that bad and don’t include intestinal distress. That’s a dangerous assumption, given that more than half of adults who have celiac disease don’t have intestinal symptoms. Poor absorption of nutrients is more likely to manifest in neurological symptoms such as “brain fog” and headaches, as well as anemia and osteoporosis.

When someone with celiac disease doesn’t have obvious symptoms, it’s known as “silent” celiac disease. About half of people with celiac disease don’t know they have it — on average, someone has the disease for 12 years before being diagnosed — so do the other half have silent celiac, or are there other reasons they were never tested? That’s hard to say, but one of my former clients had a stubborn case of anemia for many years before her doctor thought to test her for celiac disease. That test was positive. Which brings me to my three reasons to not self-diagnose:

  1. If you don’t know if you have celiac disease, but go off gluten and feel better, you may not want to reintroduce gluten (a “gluten challenge”). Testing for celiac disease starts with a blood test for the enzyme IgA tissue transglutaminase (tTG) and a few other indicators. If the results are positive, an intestinal biopsy can confirm the diagnosis. Undergoing theses tests while gluten-free can yield false results. Genetic testing for human leukocyte antigens (HLA-DQ2 and HLA-DQ8) can be done while on a gluten-free diet, but it can only rule out celiac disease, not confirm that someone has it.
  2. Even trace amounts of gluten can cause intestinal damage in someone with celiac disease. Unless carefully planned, gluten-free diets may contain hidden gluten, which makes it hard even for people with diagnosed celiac disease to avoid gluten 100%. So if you feel better when you avoid gluten and think it’s OK to just play it safe by “assuming” you have celiac disease, I have news for you — gluten will find a way into your diet. Your vigilance will weaken.
  3. The real culprit of your symptoms may have nothing to do with gluten. Some people have trouble tolerating fructans — long chains of fructose — in wheat and other foods such as onions and garlic, possibly because they have irritable bowel syndrome (IBS). Plus, there are many other health conditions that share similar symptoms — and not just digestive symptoms — with celiac disease and other gluten-related conditions.