There’s no question that "going gluten-free" is the dietary trend of the day, with sales of gluten-free products estimated to be about $2.6 billion in the United States. Gluten is the main protein in wheat, barley, and rye. It is ubiquitous in our food supply, found in such fare as bread, cereal, pasta, pizza, couscous, bulgur, and beer.
In recent years, gluten has been blamed for a multitude of gastrointestinal symptoms, and eliminating it from the diet has been purported to accomplish everything from inducing weight loss and improving your ability to get a good night’s sleep to curing autism. But the No. 1 reason people give for going gluten-free is that they think these foods are healthier than their gluten-containing counterparts.
Despite a lack of research to support such claims, a recent survey found that one-third of Americans say they are trying to eliminate gluten from their diets or reduce their intake of it. Yet banning gluten can make it challenging to follow the advice from nutrition and medical experts to increase consumption of whole grains as a means of improving health and fighting chronic diseases.
If not handled carefully, a gluten-free diet can also be lacking in key nutrients, such as thiamine, riboflavin, niacin, folate, and iron. Given these concerns, who really needs to go gluten-free?
Until recently, that question was fairly easy to answer: people with celiac disease and people with a wheat allergy who are also allergic to other gluten-containing grains. Over the past decade, however, a new classification has emerged—non-celiac gluten sensitivity—an intolerance to gluten.
A growing body of research suggests that this problem is real and that people with non-celiac gluten sensitivity might benefit from reducing their gluten consumption.
A must for people with celiac disease
Epidemiologic studies estimate that only about 1 percent of people in the United States have celiac disease. This serious autoimmune disorder (a condition in which the body’s immune system attacks itself) requires strict lifelong adherence to a gluten-free diet.
When people with celiac disease consume gluten-containing products, the protein damages the lining of the small intestine, leading to an array of symptoms—including diarrhea, bloating, and weight loss—that appear within days to weeks of consuming the product.
Over time, celiac disease can cause irreparable damage to the small intestine, resulting in a dangerous inability to absorb and use nutrients in food, which in turn can lead to the development of conditions such as iron-deficiency anemia and osteoporosis.
It may not be the gluten, but rather the wheat
Far fewer people—approximately 0.1 percent of individuals in Westernized nations—are allergic to wheat. A wheat allergy is an overreaction of the immune system specifically to wheat protein.
Symptoms of a wheat allergy, which include swelling, itching, hives, and/or difficulty breathing, occur within minutes or hours of consuming something that contains wheat. In some cases, the reaction may be life-threatening.
If you are allergic to wheat, you should avoid it but not necessarily other gluten-containing grains such as rye and barley. This means you may not need to restrict your diet to gluten-free foods.
Ask your doctor about getting allergy tests to determine whether you are allergic to other gluten-containing grains. If you’re not, rather than going gluten-free, you can just avoid wheat (and wheat species, such as durum and spelt).
For packaged foods, check the list of ingredients. Because wheat is a potential allergen, federal law requires that all packaged foods containing the grain list it on the label.
Non-celiac gluten sensitivity
First described in the late 1970s, non-celiac gluten sensitivity has only recently begun to be acknowledged by researchers as a real medical condition. According to a 2015 report in Gastroenterology, there is “increasing and undisputable evidence” for its existence.
Typical symptoms of non-celiac gluten sensitivity include bloating, stomach pain, diarrhea or constipation, and nausea. Symptoms appear within hours or days of ingesting gluten-containing foods and disappear quickly when these foods are eliminated from the diet. Non-gastrointestinal symptoms, including headache, lack of energy, joint and muscle pain, and “foggy brain” have also been noted.
Diagnosis is difficult, as there are no blood tests or other ways to identify the condition. However, in addition to the symptoms previously discussed, the presence of other clues may suggest non-celiac gluten sensitivity.
For example, many people with gluten intolerance are intolerant to other foods, such as cow’s milk or eggs. They also tend to have a history of allergy dating back to childhood.
Also, while some of the gastrointestinal symptoms are similar to those experienced by people with irritable bowel syndrome (IBS), the presence of nongastrointestinal symptoms (not experienced by everyone with non-celiac gluten sensitivity) makes it easier to rule out IBS as a cause.
In spite of doctors’ improved understanding of non-celiac gluten sensitivity, questions remain, including why it occurs and how many people it truly affects. Current estimates suggest that 0.6 to 6 percent of the population may have non-celiac gluten sensitivity. The condition occurs most commonly in women in their 20s and 30s, but it can arise at any age.
Why does it occur? At this point, researchers aren’t really sure.
Early evidence suggests that non-celiac gluten sensitivity is the result of an aberrant immune system response to gluten, though not the same type of response seen in celiac disease or other autoimmune disorders, in which the body turns on itself. Nor is it the same as an allergic reaction, which occurs when the immune system overreacts to a harmless substance. Some researchers think a genetic component may be involved.
Clearly, more research is needed to help doctors better understand why some people develop non-celiac gluten sensitivity and what the long-term implications of the condition are. For now, the good news is that it does not appear to be associated with serious adverse effects, such as poor absorption of nutrients from foods or intestinal damage, and it is not life-threatening.
Getting a diagnosis
Non-celiac gluten sensitivity is diagnosed by excluding both celiac disease and wheat allergy. Many individuals self-diagnose and treat the condition by reducing gluten-containing foods in their diets.
However, before you eliminate gluten from your diet, it’s important to get tested for celiac disease and wheat allergy to rule those conditions out; otherwise those test results may be inaccurate. If you do have either of these conditions, you’ll want to consult a nutritionist to help you navigate your food choices at home and when eating out.
If you don’t have celiac disease or a wheat allergy but you are experiencing symptoms suggestive of non-celiac gluten sensitivity, experts advise keeping a food diary. Record your symptoms in response to your regular diet, including gluten-containing foods, for 10 to 14 days. Then continue the food diary while you eliminate all gluten-containing foods for another 21 days. Finally, do a food challenge: Start reintroducing suspect foods into your diet one at a time to see if they trigger symptoms.
If you are gluten-intolerant, you’ll want to focus your diet on naturally gluten-free foods such as fruits, vegetables, beef, poultry, fish, nuts, and eggs.
You can still consume grains that don’t contain gluten, such as amaranth, buckwheat, corn, millet, quinoa, rice, sorghum, and teff, as well as flax, lentils, potatoes, and soy. Many experts also believe that oats (if they are from a source that has not been contaminated by wheat, rye, or barley) are not harmful to people with non-celiac gluten sensitivity and even most individuals with celiac disease, and they are a source of significant, much-needed nutrients in the diet.
A host of commercially prepared gluten-free products are also now available, and they are far more palatable than they were in the past. It’s important, however, to check the labels of these products to see what they contain.
To replace gluten, many products are higher in sugar, calories, and fat than their regular counterparts, which may lead to weight gain.
Finally, if you’re following a gluten- or wheat-free diet, it’s a good idea to talk to your healthcare provider or a nutritionist to see if you should be taking a multivitamin to ensure you’re getting all of the nutrients your body needs.
And since it’s unclear if gluten sensitivity is a permanent condition, think about reintroducing gluten and wheat products back into your diet periodically—say, annually—to determine if you’re still sensitive to them.