A gluten-free diet is the main treatment for people with celiac disease. Many people without this condition are also going gluten-free for its supposed health benefits.
Gluten is a protein found in wheat, barley, and rye. This protein helps foods hold their shape. Most cereals, breads, and pastas contain gluten.
Some people have an intolerance to gluten. Celiac disease is an autoimmune condition in which gluten damages the small intestine, and nonceliac gluten sensitivity is a food intolerance that leads to discomfort after eating gluten.
However, a survey by a market research company found that up to 30% of adults in the United States are trying to reduce or eliminate gluten from their diet. Many of them do not have celiac disease.
For people without a gluten intolerance, does a gluten-free diet have any health benefits or risks?
When people with celiac disease consume gluten, their immune system attacks and damages the lining of their small intestine. With repeated exposure to gluten, the body becomes less able to absorb nutrients into the bloodstream.
Complications can arise if a person with celiac disease continues to eat gluten, such as:
- nutrient deficiencies
- weight loss
- multiple sclerosis (MS)
- neurological conditions
Nonceliac gluten sensitivity is considered less severe than celiac disease. Eating gluten does not damage the intestine, but people may experience discomfort after eating gluten.
Symptoms of gluten sensitivity often arise outside the digestive system and can include:
- brain fog
- joint pain
- numbness in the extremities
Researchers believe that more people have gluten sensitivity than celiac disease. Estimates vary, but it may affect between 0.5% and 13% of people.
A strict gluten-free diet is the only effective treatment for celiac disease and gluten sensitivity.
Is gluten sensitivity real?
Many countries recognize that nonceliac gluten sensitivity is a problem. However, this is a new area of study, and researchers do not yet understand the condition, its risk factors, or how common it is.
Some researchers have suggested that, rather than reacting to gluten in foods, people are sensitive to fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), which are other non-gluten proteins found in wheat.
FODMAPs are present in gluten-containing grains. This could explain why people with IBS show improvement in symptoms when on a gluten-free diet.
While there are many documented cases of possible nonceliac gluten sensitivity, more research is needed before scientists understand the causes, symptoms, and effects of gluten sensitivities.
There is little scientific evidence that a gluten-free diet has health benefits for anyone without celiac disease or a nonceliac gluten sensitivity.
Despite this, a report from the National Health and Nutrition Examination Survey (NHANES) states that around 2.7 million people without celiac disease were following a gluten-free diet between 2009 and 2014.
The authors of this report suggest the following reasons for the wider population adopting a gluten-free diet:
- public perception that a gluten-free diet is more healthful and may improve nonspecific gastrointestinal symptoms
- gluten-free products are now more widely available
- a growing number of people are diagnosing themselves with a gluten sensitivity and they have noticed that their gastrointestinal health has improved after cutting out gluten
While doctors can diagnose celiac disease using blood tests, breath tests, and biopsies, there are no specific diagnostic tests for gluten sensitivity. Many people may have a gluten intolerance without knowing it.
If a person has an undiagnosed gluten intolerance, such as celiac disease or gluten sensitivity, they may find that cutting out gluten improves their symptoms.
However, if a person suspects that they have a gluten intolerance, it is best to speak to a doctor for an accurate diagnosis before eliminating gluten from the diet.
Foods that contain gluten are important sources of nutrients, including protein and iron. When not done carefully, gluten-free diets can lead to deficiencies.
What about autism, epilepsy, and schizophrenia?
Some people are concerned that gluten could be linked with developmental differences or medical conditions. This is a misconception. While gluten intolerance may be more likely in these populations, there is no evidence that eating gluten causes these differences.
The following sections explore this in more detail.
Some people believe that gluten may exacerbate or cause behaviors related to autism. However, a 2017 review concluded that there is little evidence that a gluten-free diet has benefits for the symptoms of autism in children.
There may be a link between celiac disease and epilepsy.
In a small 2016 study of 113 people with epilepsy, around 6% tested positive for celiac disease.
In this study, 6 out of 7 of these patients had their seizures completely under control and were able to discontinue antiepileptic medications after 5 months on the gluten-free diet.
This suggests that people with epilepsy and celiac disease will benefit from a gluten-free diet.
People with schizophrenia may be more likely to have celiac disease.
A 2018 review found that a gluten-free diet may benefit a subpopulation of people with schizophrenia who have a sensitivity to gluten.
However, more research is needed before recommending a gluten-free diet for a person with schizophrenia.
The benefits and risks of gluten-free diets remain controversial. Rafe Bundy, a nutritionist and spokesperson for the Association for Nutrition, told Medical News Today:
“There are many people around the world that consume a diet which is naturally gluten-free or low in gluten. A good example is most of Asia, where the main staple food is rice, not wheat. It’s perfectly possible to have a healthy diet which is also a gluten-free diet using most standard dietary advice.”
However, removing gluten from the diet without care can, in some cases, have adverse effects. The following sections explore why.
Whole grains, such as whole wheat bread, contain important nutrients. In addition, many products that contain gluten, such as breakfast cereals, are also fortified with vitamins.
Avoiding foods that contain gluten, without adding other nutrient sources to the diet, can lead to deficiencies. Deficiencies may include:
Lack of fiber
Many products that contain gluten are high in fiber. When following a gluten-free diet, it is important to get dietary fiber from other sources, such as beans, lentils, nuts, seeds, and gluten-free whole grains.
A 2017 review concluded that avoiding gluten could lead to a reduced intake of heart-healthy whole grains, which may affect a person’s risk of cardiovascular disease.
To stay healthy and avoid symptoms, a person with a gluten intolerance needs to avoid all foods that contain gluten, even in the smallest amounts.
Foods that contain gluten include:
- any food made with cereals such as wheat, barley, triticale, rye, and malt
- some candies
- many desserts
- cakes and pies
- french fries
- processed meats
- sauce mixes
- brown rice syrup
- malt derivatives, including malt loaf, malt vinegar, brewer’s yeast, and malt based beer and malted milk or milk shakes
- some types of soy sauce
- self-basting meat
Other items, especially processed foods, can contain hidden gluten. Anyone who needs to follow a gluten-free diet should check the food label to make sure there is no gluten in the product.
Products sold as gluten-free may contain traces of gluten, especially if they were made in a factory that also produced regular wheat based products.
Non-food items that may contain gluten include:
- lipstick, lip gloss, and lip balm
- play dough
- medications and supplements
- communion wafers
Many foods are naturally gluten-free. These include:
- fruits and vegetables
- fresh meats
- fish and poultry
- unprocessed beans
- seeds and nuts
- most dairy products
- white rice
- grains such as buckwheat, corn and cornmeal, flax, quinoa, rice, soy, arrowroot, and millet
If any product may have come into contact with grains, preservatives, or additives that contain gluten, a person with celiac disease should avoid it.
A wide range of gluten-free alternatives, including breads and pastas, are now available in grocery stores. Gluten-free products are also available for purchase online through Amazon.
According to the Food and Drug Administration (FDA), food manufacturers can choose to use the label “gluten-free” on their products if the item contains less than 20 parts per million of gluten.
Anyone who is thinking of eliminating gluten from their diet should take some steps to prepare. These can include:
- discussing with their doctor any gastrointestinal symptoms, such as chronic or severe abdominal pain, bloating, or diarrhea, as the doctor may need to assess for other conditions
- continuing to consume gluten until they have been tested for celiac disease, as cutting out gluten may lead to a false negative test result
- talking to a dietitian before cutting out gluten, to make sure the diet will include all the essential nutrients
Despite popular trends, there is little evidence that a gluten-free diet has health benefits for people who do not have a gluten intolerance such as celiac disease or nonceliac gluten sensitivity.
A gluten-free diet is the only effective treatment for celiac disease.
When a person is removing sources of gluten from their diet, it is important that they get adequate nutrients from other dietary sources.