According to Harvard Medical School’s Harvard Health Letter, about 20 to 30 percent of Americans are following a gluten-free diet. Gluten is a protein found in grains, including wheat, barley, rye, and oat. People with celiac disease or a wheat allergy need to avoid gluten, but only about 1 to 2 percent of people have these conditions, so why are all the other people avoiding gluten?

Most people on a gluten-free diet either claim to have gluten sensitivity or think that a gluten-free diet is healthier for them. Surveys show that most people go gluten-free because they believe that gluten-free foods are a healthier option for digestive health. Gluten sensitivity was first recognized about 30 years ago. Symptoms may include crampy pain, bloating, gas, brain fog, diarrhea, nausea, headache, or fatigue. Because gluten sensitivity does not cause any changes that can be measured with diagnostic testing, doctors have been slow to accept it as a real condition.

Today, to be diagnosed with gluten sensitivity, or non-celiac gluten intolerance, you need to go to a doctor to rule out celiac disease and wheat allergy with a blood test or skin testing. You would then go on a gluten-free diet for several weeks to see if your symptoms go away, and then reintroduce gluten to see if they come back. Not surprisingly, most people who say they are gluten sensitive or gluten-intolerant are self-diagnosed.

A recent commentary in the journal Digestive Diseases and Sciences notes that when tested under research conditions, few people with gluten sensitivity symptoms test positive for non-celiac gluten intolerance. Available studies suggest that only about 6 percent of the 20 to 30 percent of Americans going gluten free need to avoid gluten.

What’s causing the symptoms?

When people with symptoms of gluten intolerance are given a placebo instead of actual gluten under double-blinded study conditions (neither the subjects nor the researchers know who is getting real gluten or fake gluten), as many people given the placebo as the gluten may have sensitivity symptoms. These people may be experiencing what is called the nocebo effect. Nocebo is a well-documented response in clinical studies. When people expect to get certain symptoms or side effects, they are more likely to get them.

Undoubtedly, there are people without celiac disease or wheat allergy who really do react to foods that contain gluten, but evidence is growing that gluten may not be the main culprit. Most researchers now believe that these symptoms are caused by FODMAP foods, not gluten. These are sugars in foods, including wheat and other grains, that are rapidly fermented in the intestines and create gasses that cause pain, bloating, and diarrhea.

FODMAP is an acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. For some people, these sugars are hard to digest and are poorly absorbed in the small intestine. People with FODMAP intolerance can have the same symptoms as gluten intolerance. Treatment of FODMAP intolerance requires a very restrictive elimination diet to find out what foods you need to avoid. This diet should be supervised by a dietitian. Along with grains, FODMAP foods may include dairy, beans, specific vegetables, and some fruits. People react differently to different foods.

Is gluten bad or good for you?

According to the Harvard School of Public Health, gluten-free foods are a rapidly growing food industry worth about $12 billion in 2015 and much more today. Media campaigns have spawned gluten-free cookbooks, restaurants, food aisles, and celebrities. The vast majority of people supporting this industry do not have celiac disease or wheat allergy. They may not even have any intolerance symptoms. The gluten-free food industry claims that the gluten-free lifestyle is healthier and, without any evidence, blames gluten for everything from autism and heart disease to acne.

The Harvard School of Public Health notes that many studies consistently show people who include more whole grains in their diet (and more gluten) have less heart disease than people who eat less grains. Harvard also warns that gluten-free foods tend to be highly processed with lots of sugar, salt, calories, and saturated fats. Gluten-free foods are low in fiber, vitamins (especially B vitamins), nutrients, and iron. In fact, people with celiac disease, who need to avoid gluten, have an increased risk of obesity, high blood pressure, and diabetes. Gluten-free foods are also more expensive than most whole foods.

Bottom line on gluten-free

If gluten foods do not cause any symptoms, like cramps, gas, or bloating, you don’t need to go gluten-free. There is no advantage to avoiding gluten for you. In fact, it may be unhealthy. If you do have symptoms after eating gluten, you should check in with your doctor. Even if going gluten free makes you feel better, don’t diagnose yourself with gluten sensitivity.

Anyone on a gluten-free diet should be on a diet that is also low in fat and high in fiber, and should get regular blood testing to check for anemia, iron deficiency, vitamin B deficiency, high cholesterol, and high blood sugar. If you really are sensitive to gluten, you should work with your doctor and a dietitian to make sure you are getting as much nutrition and fiber from your diet as possible.

Another reason to get checked is that you may have another condition that needs treatment. Your symptoms could be due to celiac disease, wheat allergy, other food allergies, irritable bowel syndrome, inflammatory bowel disease, lactose intolerance, or FODMAP intolerance. A FODMAP elimination diet is more complicated than just avoiding gluten, and many people who have celiac disease do not know they have it. All these conditions require the right diagnosis and treatment. So, don’t self-diagnose, and don’t be fooled by the benefits of a gluten-free lifestyle.

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