Gluten is the general term for the proteins found in cereal grains, including wheatberries, durum, emmer, semolina, spelt, farina, farro, Graham, kamut (Khorasan wheat), einkorn, rye, barley, and triticale (a cross between wheat and rye). Gluten is sticky and acts like glue, holding foods together and helping them retain their shape.

Gluten is present in many types of food, including some you’d never expect, according to the Celiac Disease Foundation. It’s also found in nonfood products, including lipstick and lip balm.

The Controversial Popularity of the Gluten-Free Diet

The gluten-free diet has become quite popular within the past few years. Interestingly, some people who are committed to a gluten-free dietary approach can’t articulate why they tried it or how they benefit from it. But they adamantly claim that they “feel better.”

That said, the gluten-free diet has become a bit controversial. Some sources suggest that more people have tried to reduce or eliminate gluten from their diet than ever needed to. According to one poll, 1 in 5 Americans have tried to include gluten-free foods in their diet. Some of the people who have switched to a gluten-free diet believe it is healthier, while others believe it can help them to lose weight. Others have tried to positively impact a chronic disease by making the dietary change. This is where the questions come in:

Which diseases and conditions are helped by a gluten-free diet?
Is a gluten-free diet generally healthier?
Is a gluten-free diet totally harmless?

Let’s consider the evidence.

Diseases and Conditions That May Improve With a Gluten-Free Diet

Some reports have suggested that there is evidence a gluten-free diet may improve symptoms associated with rheumatoid arthritis, as well as irritable bowel syndrome, type 1 diabetes, and dermatitis herpetiformis.

There are, however, three undisputed conditions that warrant avoiding gluten in your diet:

Allergy to wheat
Celiac disease
Nonceliac gluten sensitivity, in which people don’t test positive for celiac disease but have the same symptoms, which disappear by eliminating gluten from their diets

As for how a gluten-free diet may affect the other conditions where widespread evidence is lacking, it is still possible that some individuals may experience beneficial effects. Does that make it worth a try? You decide. If you want to give it a go, consider an elimination diet — after consulting your doctor for guidance.

Gluten, Inflammation, and Rheumatoid Arthritis: What Studies Have Shown

Theories about the possible effects of gluten on rheumatoid arthritis date back at least to the 1960s, when Australian physician R. Shatin hypothesized that people with celiac disease and those with rheumatoid arthritis share a genetic similarity.

As described by others in JAMA, Shatin believed that in RA, “the intestinal mucosa is abnormal and important metabolites essential to connective tissue are not absorbed,” resulting in symptoms of RA. Shatin tested his theory by having 18 RA patients follow a gluten-free diet, and he reported that all 18 improved.

In the decades that followed, other researchers have tested gluten-free diets on people with RA, but they’ve often made other dietary modifications at the same time, such as having subjects follow a gluten-free vegan or vegetarian diet, making it difficult to know which dietary changes caused the observed effects.

In one study, for example, 66 people with active RA were randomly assigned to either a gluten-free vegan diet or a nonvegan diet for one year. Neither diet was shown to protect against joint destruction, but more participants in the gluten-free vegan group had improvements in measurable signs and symptoms of RA, which researchers associated with a reduction in antibodies to food antigens, including gliadin, which is one of the proteins that make up gluten.

In a subsequent study, data from the earlier study was analyzed to see what effect the gluten-free vegan diet had on cholesterol and other lipid levels. Researchers concluded that it lowered total cholesterol, LDL (low-density lipoprotein), and oxLDL (oxidized LDL), and raised levels of natural antibodies that are negatively associated with the development of atherosclerosis. The researchers hypothesized that the beneficial results could contribute to protecting against cardiovascular disease in RA patients, but larger studies were needed.

Some research has focused not on the effects of dietary changes but on the presence of anti-gliadin antibodies in people with rheumatoid arthritis.

One study concluded that anti-gliadin antibodies are detected far more frequently in patients with RA and primary Sjögren’s syndrome, another chronic autoimmune disease, compared with the general population.

However, being positive for anti-gliadin antibodies does not necessarily mean a person has gluten sensitivity, as is explained in a review of possible biomarkers for nonceliac gluten sensitivity.

Most recently, in an article published in 2022, a team of researchers looked at 16 articles, dating back to 1991, on gluten-free diets in people with rheumatoid arthritis. Some of those articles described clinical research, while others were literature reviews. The authors of the 2022 article noted a number of shortcomings to the clinical studies, including their small size and the fact that in most of them, the elimination of gluten was not the only dietary modification. The authors’ conclusion? “No scientific evidence has been found to promote the exclusion of gluten in rheumatoid arthritis patients without celiac disease or NCGS [nonceliac gluten sensitivity].”

They further concluded: “Clinical trials with exclusion diets, with gluten as the only factor to be excluded, are needed to demonstrate conclusively whether gluten exclusion improves the symptoms of patients with rheumatoid arthritis.”

While the studies have revealed a hint of a connection between gluten and RA symptoms, we are still left with too few studies and studies that are very small in scope. According to one meta-analysis, there is nothing yet that confirms a widespread connection.

Is a Gluten-Free Diet Generally Considered Healthy?

If you have chosen to try a gluten-free diet, you are left focusing on gluten-free products available in a dedicated section of your local grocery store. The good news is that there are more gluten-free products available now than ever before. The bad news is that they can be quite expensive. More bad news — gluten-free products are often high in sugar and fat and low in fiber. Consequently, you may experience constipation and weight gain.

Wheat is considered a nutritious grain. Many wheat-containing products (for example, breads and cereals) are fortified with vitamins and minerals. To eliminate all wheat products creates a void in your diet. When medically necessary, that void must be compensated for. When gluten-free is just a choice, there must be an awareness of the nutritional void that is created, and it should not be ignored.

Very likely the better approach to dietary management of RA goes beyond simply eliminating gluten. It would be optimal to focus on the “ideal food pyramid for patients with rheumatoid arthritis,” as outlined in a study review.

Is a Gluten-Free Diet Considered Harmless?

A gluten-free diet cannot be deemed harmless because of its potential for nutritional deficiencies. If you do not have celiac disease or evidence of gluten sensitivity, there is no reason to follow a gluten-free diet.

If you have a condition like rheumatoid arthritis where testimonials exist, along with some limited scientific evidence about the beneficial impact of a gluten-free diet, talk to your doctor about your desire to try it.

Follow their advice and guidance so that you can avoid nutritional deficiency and can pay attention to your intake of additional sugar and fat, as well as the diet’s effect on your weight.

Editorial Sources and Fact-Checking

Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

Resources

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Dermatitis Herpetiformis. Cleveland Clinic. December 2, 2022.
Binder H et al. Gluten and the Small Intestine in Rheumatoid Arthritis. JAMA. March 7, 1966.
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