Is Gluten Bad for You? A RD Makes Sense of Who Should (and Shouldn’t) Avoid It

Gluten has gotten a bad rap over the past several years, being blamed for bloating, “brain fog,” weight gain, and other untoward ailments. Because of these concerns, the gluten-free product industry has soared. According to a 2017 study in the UK, gluten-free products are 159% more expensive than conventional food, along with being higher in fat, salt, and sugar.

With that kind of cost, is a gluten-free diet healthy or really necessary? 

Let’s take a deeper dive into gluten. We’ll uncover the sources of gluten and research-based reasons for when and why a gluten-free diet is truly indicated.

Got Gluten: What Contains Gluten & Why You Can’t Always Trust Labels

Despite the hype, gluten isn’t evil; it’s simply a protein found in barley, rye, and wheat. Gluten in bread gives dough elasticity, texture, and flavor. It’s found naturally in the above grains and can be added to foods as a binding agent. Most foods that contain gluten are good sources of dietary fiber.

Any grains containing wheat, whether refined, enriched, or whole, will contain gluten. These include pantry staples like bread, pasta, bran or wheat cereals, crackers, and flour. Triticale, farro, bulgur, spelt, and cracked wheat are whole grains that are less commonly known sources of gluten. Despite the name, buckwheat doesn’t contain gluten.

Boxed cake, cookie, and brownie mixes, mac and cheese, or other pasta dishes will contain gluten. It can be hidden in frozen meals, snacks, and condiments such as soy and BBQ sauces. Beer and rye bread or crackers will also contain gluten. Medications, supplements, and even beauty products could have hidden gluten as well.

While oatmeal is not a source of gluten, it can be contaminated with gluten if it’s processed in a facility that makes products that contain gluten. According to the FDA, a food must have less than 20 parts per million of gluten to be labeled “gluten-free.” This labeling claim is voluntary.

Who Actually Needs Gluten-free 

While the popularity and abundance of gluten-free foods do not seem to be slowing down, the number of people that actually need a gluten-free diet is minimal. The most important group is individuals with a diagnosis of Celiac disease, though others could benefit. 

Celiac disease is an autoimmune condition that impacts digestion and damages the small intestine. The condition is triggered when someone eats even the smallest amount of gluten. Individuals with celiac disease often experience abdominal pain, discomfort, and malabsorption; stunted growth, iron deficiency, and vitamin D deficiency are also common in celiac disease. 

The CDC estimates that 1 in 141 people (.71%) suffer from celiac disease in the U.S., while globally, Celiac disease impacts 1.4% of the population and is more common in white adults. 

Non-celiac gluten sensitivity impacts about 6% of the population. This is a less serious condition than celiac disease, as it doesn’t involve the immune system, though individuals may have stomach discomfort, headaches, or other side effects from eating gluten.

Celiac disease is not the same as an allergy to wheat, which occurs when a person has an allergic reaction to wheat. They may experience itching, headache, nasal congestion, trouble breathing, nausea, vomiting, cramps, diarrhea, or swelling in their mouth or throat when they eat wheat. Their bodies have built up antibodies to proteins found in wheat and react when it’s consumed. Avoid wheat-containing foods if you have this allergy.

Thyroid Disease, Diabetes & Other Conditions

Individuals with other autoimmune and non-autoimmune conditions may benefit from a gluten-free diet. Type 1 diabetes is a hereditary, autoimmune condition that is seen primarily in children. A recent systematic review of studies estimates that 4 to 5% of people with type 1 diabetes also have celiac disease. 

The two conditions share a common genetic background. Consuming cow’s milk and gluten under four months of age and having early viral infections have been linked with the development of each disease.

Other research hints that a gluten-free diet may help prevent type 1 diabetes. Gluten peptides (proteins) are thought to cross the intestinal barrier and cause inflammation. When these peptides reach the pancreas, they may change beta cells, causing alterations in insulin secretion. Animal studies and one human study have shown that gluten-free diets during pregnancy may lower the risk of type 1 diabetes in children.

Other research suggests an association between celiac disease and autoimmune thyroid diseases such as Hashimoto’s and Grave’s disease, as well as between non-celiac wheat sensitivity and thyroid disease. 

The rationale behind this connection is based on a cross-reaction of antibodies, poor absorption of nutrients needed for thyroid function, and leakage of intestinal toxins. Eliminating gluten has been advised because of possible interactions of gliadin (a protein in gluten) with thyroid antigens.

A gluten-free diet may alleviate the pain of rheumatoid arthritis, an inflammatory autoimmune disease. A study of 40 patients with obesity or overweight and longstanding rheumatoid arthritis evaluated the impact of three months on the privative diet — where meat, gluten, lactose, and all dairy products are excluded. This diet was compared with a control balanced diet that included those foods.

Participants on the privative diet showed improvement in overall physical and mental health. They experienced a significant reduction in blood pressure as well as a decrease in labs that reflected markers of inflammation.

Scientists note that observational and anecdotal cases cite a link between gluten and autoimmune diseases such as rheumatoid arthritis, and conclude that gluten may have an inflammatory effect that impacts gut bacteria.

Gluten-free for IBS?

Speaking of your gut, one final condition that may respond to a gluten-free diet is IBS (irritable bowel syndrome), a functional gastrointestinal disorder with symptoms that include abdominal pain, gas, bloating, and diarrhea. Some people may experience constipation.

Research suggests gluten may trigger IBS, as gut enzymes may not break down the protein gliadin (found in gluten). This could lead to an immune response and inflammation. 

In a randomized controlled trial of 34 subjects with IBS and without celiac disease, those who ate gluten for one week after following a gluten-free diet for six weeks reported worsened gastrointestinal symptoms, including abdominal pain, bloating, and changes in their stool, compared with the placebo group.

A more recent study of 103 participants found that consumption of FODMAPs (fermentable carbohydrates that may trigger IBS) led to modestly higher IBS severity scores than intake of gluten or placebo alone. Differences were not seen between the placebo group and the group that ate gluten.

A Word of Caution with Gluten-free

Gluten-free grains, cereals, and bread are typically lower in fiber than traditional wheat-containing foods, so a gluten-free diet may not necessarily be healthier for you. To date, no research supports that gluten-free diets aid weight loss or other health outcomes. 

Studies examining weight and other health outcomes in those with celiac disease have seen weight gain and higher risks for heart disease. This is likely related to the lack of fiber and other nutrients such as folate, calcium, and iron in a gluten-free diet. 

Gluten-free diets should be reserved for certain chronic medical conditions and should be prescribed by a physician or other healthcare provider. A registered dietitian may help you plan a gluten-free diet if it’s truly needed.

What to Eat if You Need a Gluten-free Diet

If you suspect that you have celiac disease, do not immediately remove gluten from your diet. Your body has to have exposure to gluten to show an immune reaction. Removing gluten from your diet prior to being tested for celiac disease could result in a false negative test.

Individuals with celiac disease must avoid gluten for life. Ideally, everything in their kitchen should be gluten-free. Cross-contamination from other gluten-containing grains is a risk in restaurants, grocery stores, bakeries, delis, or pizza parlors that serve food containing gluten.

If you or someone you know has celiac disease or any of the mentioned conditions above, there are plenty of other grains to eat. Gluten-free grains include amaranth, buckwheat, corn, millet, oatmeal, rice, potatoes, quinoa, sorghum, and teff. There are pastas, pizzas, and foods made from cauliflower, beans, and lentils that are popular and tasty.

Look for the words “gluten-free” on packaged foods and avoid packaged foods that may contain gluten such as hot dogs, salad dressing, ice cream, snack foods, and certain condiments. Terms such as modified wheat starch, barley, maltodextrin, or malt mean the food contains gluten.

Include other high-fiber foods in your diet such as beans, lentils, and other legumes, brown rice, quinoa, and plenty of fruits and vegetables. 

Gluten-free has its place in certain medical conditions. The majority of people should save their money and keep the wheat.