Unfortunately, it's frequently far from that easy. Studies and anecdotal evidence indicate that a fairly high percentage of people with celiac and gluten sensitivity — it's not clear exactly how high, but possibly upwards of half — continues to have symptoms even though they believe they're following a strict gluten-free diet.
This can be incredibly discouraging, and it frequently leads people to believe they've become intolerant to numerous other foods (soy usually heads the list, with corn and other grains not far behind). However, at least one study involving celiac patients shows that the majority actually are suffering the effects of ongoing gluten ingestion — not "additional intolerances" to various foods, or some other problem.
Why Is It So Tough To Be Perfectly Gluten-Free?
Gluten is everywhere, and in people with celiac and gluten sensitivity who react to very small amounts, it can be nearly impossible to avoid. It can hide in places you don't expect, such as prescription medications and gourmet meats (see more about this in Gluten-Free Diet Dangers). It also can appear in trace amounts in foods that appear gluten-free by their ingredients lists.
In many cases, grain-based "gluten-free" products are top suspects. For example, a 2010 study of gluten in "gluten-free" grains found gluten cross-contamination in amounts ranging from barely detectable (around 5 parts per million) to nearly 3,000 parts per million (enough to cause an epic glutening).
Celiac disease experts, including Peter Green, MD, director of the Celiac Disease Center at Columbia University, say that helping patients with ongoing symptoms despite a careful gluten-free diet is a major priority. In 2011, Dr. Green said that a drug designed to mitigate the effects of cross-contamination would be a huge boon to celiac patients with ongoing symptoms (see more on this: Dr. Green: Celiac Drug Treatment Shows Tremendous Potential).
So How Many People Are Affected By Continuing Symptoms?
That's not clear, although there are some hints in the medical literature for people with celiac disease. (There aren't any studies touching on gluten sensitivity, but anecdotal evidence indicates many of those with that condition also suffer from ongoing symptoms.)
In a 2003 study published in the American Journal of Gastroenterology, researchers studied a group of adult celiacs who had been gluten-free for between eight and 12 years. They found the subjects with celiac disease reported "significantly more gastrointestinal symptoms than the general population," including indigestion, diarrhea, constipation, abdominal pain and reflux.
In fact, some 60% of those celiacs studied experienced frequent symptoms, compared to 29% of the general population. Women tended to fare worse than men.
Another study of "irritable bowel-type symptoms" in people who had been diagnosed with celiac disease a year ago or more found that more than 23% suffered from continuing bowel symptoms that were serious enough to meet the criteria for irritable bowel syndrome (IBS), and most sought help for their symptoms. Those with IBS symptoms were more likely to be female and to stray occasionally from the gluten-free diet, the study found.
In that study, people with IBS symptoms also were more likely to have a "probable mental disorder," as determined by a questionnaire that looked for signs of anxiety and depression. However, it should be noted that many people with celiac disease report symptoms of anxiety and depression when they ingest small amounts of gluten; for more on this, see Gluten and Anxiety and Gluten and Depression.
Another study looked at 112 patients referred to a London hospital with non-responsive celiac disease (12 of whom, it turned out, didn't have celiac disease after all). Of the remaining 100 people, the study found that 45% "were not adequately adhering to a strict gluten-free diet," with slightly more than half of those inadvertently ingesting gluten and slightly under half intentionally cheating.
Finally, an unpublished study presented by Alvine Pharmaceuticals at a 2012 medical meeting found that a "large" (but unspecified) percentage of diagnosed celiacs continue to experience symptoms despite adhering to a strict gluten-free diet.
Those symptoms listed by subjects in the Alvine study sound like a laundry list of typical celiac complaints: flatulence, abdominal pain, fatigue, bloating, diarrhea, constipation, nausea, brain fog, headaches and skin rashes. They're also discouragingly frequent: 90% of those studied said they had at least one day of symptoms in a week's time, and 44% said they experienced five to 10 different symptoms in a week. (For more on the study, see: Study: Gluten Ingestion Symptoms Frequent Despite Gluten-Free Diet)
What Can You Do If You Still Have Symptoms?
Your first step should be to consider a trip to your doctor to make certain you haven't been misdiagnosed. In one of the studies I wrote about above, 11% of those with diagnosed celiac disease and continuing symptoms turned out not to have celiac disease at all! Others may have both celiac disease and another condition that's causing their continuing symptoms. Keep in mind, though, that even if you weren't diagnosed correctly with celiac disease, you could still suffer from gluten sensitivity. The treatment is the same for both: a strict gluten-free diet.
If you're confident gluten is your problem, then you probably need to examine your diet for hidden gluten. Start with the top offenders listed in my Gluten-Free Diet Dangers article (link above).
If you're not consuming any of those, take a hard look at the rest of your diet: restaurant meals, lots of processed foods (even if they're labeled "gluten-free") and an over-abundance of "gluten-free" grain products might lead you to ingest more trace gluten than your body can handle. Pay particular attention to the testing levels for your favorite "gluten-free"-labeled products — you may need to eat only certified gluten-free products or to avoid most grains, since they tend to be quite contaminated with gluten.
Here's some more resources on eradicating trace gluten from your diet:
- How Much Gluten Can Make Me Sick?
- Foods Labeled 'Gluten-Free' May Still Contain Some Gluten
- Why You Can Eat Gluten-Free and Still Get Symptoms
- Major Gluten Exposure vs. Trace Gluten Exposure
- Why Gluten-Free Products' Parts Per Million Numbers Matter
- Gluten PPM Table - Learn Manufacturers' Testing Levels
In some cases, you may need to look into whether you're reacting to foods other than gluten — it's common for people with celiac disease to also have lactose intolerance, for example, and many people report distinctly different reactions to soy and corn, both highly allergenic foods in their own right. In many cases, though, eliminating low levels of gluten will do the trick.
If all else fails, you may want to consider consulting with a dietitian who is well-versed in the gluten-free diet — that person may be able to spot problems you may have missed, such as inadvertent cross-contamination that results from a shared kitchen, or exposures at work.
Above all, don't start to fear food — in my experience (and I'm extremely sensitive to trace gluten), it absolutely is possible to eat a varied and interesting diet that also eliminates symptoms almost completely.
Dewar D.H. et al. Celiac disease: management of persistent symptoms in patients on a gluten-free diet. World Journal of Gastroenterology. 2012 Mar 28;18(12):1348-56.
Hauser W. et al. Predictors of irritable bowel-type symptoms and healthcare-seeking behavior among adults with celiac disease. Psychosomatic Medicine. 2007 May;69(4):370-6. Epub 2007 Apr 30.
Midhagen G. High rate of gastrointestinal symptoms in celiac patients living on a gluten-free diet: controlled study. American Journal of Gastroenterology. 2003 Sep;98(9):2023-6.