Gluten-free diet

Date Updated: 12/21/2024

Definition

A gluten-free diet is an eating plan that cuts out foods that have a protein in them called gluten. Gluten helps foods keep their shape. It's found in grains such as wheat, barley and rye. It's also found in crosses of these grains, such as a mix of wheat and rye called triticale.

Some people have health conditions such as celiac disease that cause problems when they eat gluten. If your healthcare professional recommends a gluten-free diet to manage your condition, you'll have plenty of foods to choose from. Some foods that are made with gluten are available in gluten-free versions. And many foods are naturally gluten-free. These include meats, seafood, fruit, vegetables and some grains.

Purpose of a gluten-free diet

People who have celiac disease need to follow a gluten-free diet for life to manage the condition. With celiac disease, eating gluten causes the immune system to mistakenly damage the small intestine over time.

People who have other conditions linked with gluten also may need to limit or stay away from gluten. Talk with your healthcare professional to find out what type of eating plan is right for you.

Celiac disease

Celiac disease is a type of autoimmune condition. That means the immune system mistakenly attacks healthy tissues and organs. With celiac disease, gluten triggers an immune system reaction that damages the lining of the small intestine. This condition can cause digestive symptoms such as stomach pain, bloating and diarrhea. It also can lead to ongoing extreme tiredness, headaches, depression, and bone or joint pain. Over time, damage to the small intestine prevents this organ from absorbing nutrients in food.

Gluten intolerance

This condition also is known as non-celiac gluten sensitivity. It means that you don't have celiac disease, but you get some of the same symptoms after you eat gluten. Gluten intolerance does not cause the same type of damage to the small intestine as does celiac disease. A gluten intolerance might not even be caused by gluten itself. Carbohydrates called FODMAPs that are in some foods with gluten may play a role. But more research is needed. Still, a gluten-free diet seems to improve symptoms.

Gluten ataxia

This autoimmune condition sometimes happens along with celiac disease in those who eat gluten. Gluten ataxia affects some nerve tissues. It causes trouble controlling muscles that help you move around well and maintain balance or coordination. Research suggests that a gluten-free diet can help relieve gluten ataxia.

Wheat allergy

A wheat allergy happens when the immune system mistakes gluten or some other protein found in wheat for germs. The immune system reaction that follows may cause some of the same digestive symptoms as celiac disease or gluten intolerance. Sometimes a wheat allergy also can cause other symptoms such as itchy welts called hives.If you have a wheat allergy, you likely will benefit from gluten-free foods because they're not made with wheat. But you don't need to cut out other grains with gluten, such as barley and rye.

A gluten-free diet also is popular among people who don't have a gluten-related health condition. The claimed benefits of the diet are improved health, weight loss and more energy. But more research is needed.

Diet details

If you follow a gluten-free diet, you'll likely learn to be extra mindful of what you eat. It's important to pay close attention to your food choices, the ingredients found in foods and how much nutrition they have.

Allowed fresh foods

Many naturally gluten-free foods can be a part of a healthy diet:

Fresh fruits and vegetables are gluten free, but dried, frozen and canned versions may have ingredients with gluten in them, including those in sauces.
Beans, seeds, legumes and nuts in their natural, unprocessed forms.
Eggs.
Lean, nonprocessed meats, fish and poultry without seasoning.
Most low-fat dairy products including plain milk, plain yogurt and unprocessed cheese.

Grains, starches or flours that can be part of a gluten-free diet include:

Amaranth.
Arrowroot.
Buckwheat.
Corn, including cornmeal, grits and polenta labeled gluten-free.
Flax.
Gluten-free flours such as rice, soy, corn, potato and bean flours.
Hominy (corn).
Millet.
Quinoa.
Rice, including wild rice.
Sorghum.
Soy.
Tapioca (cassava root).
Teff.

Grains not allowed

Do not eat foods and drinks that contain the following:

Wheat.
Barley.
Rye.
Triticale.
Oats, unless the label says they're gluten-free.

Oats are naturally gluten-free. But they may become tainted during production with wheat, barley or rye. This is known as cross-contamination. Oats and oat products labeled gluten-free have not been cross-contaminated. But some people with celiac disease may have a reaction to another protein in oats called avenin. Ask your healthcare professional if it's OK to include gluten-free-labeled oats in your diet.

Wheat terms to know

There are different varieties of wheat, all of which contain wheat gluten:

Couscous.
Durum.
Einkorn.
Emmer.
Farro.
Graham.
Kamut.
Spelt.
Wheat germ.
Wheat bran.

Wheat flours have different names based on how the wheat is milled or the flour is processed. All of the following flours have gluten:

Enriched flour with added vitamins and minerals.
Farina, milled wheat usually used in hot cereals.
Graham flour, a coarse whole-wheat flour.
Self-rising flour, also called phosphate flour.
Semolina, the part of milled wheat used in pasta and couscous.

Gluten-free food labels

When you buy processed foods, you need to read labels to find out if they have gluten in them. Processed foods are foods that have been changed from their natural state. They're often prepared or packaged. Check the ingredients list on a package's label. See if the list includes wheat, barley, rye or a cross of these grains such as triticale. Some packages list wheat as a possible allergen in a statement at the bottom of the label.

In the United States, foods that are labeled gluten-free must have fewer than 20 parts per million of gluten. Foods with these labels may include:

Naturally gluten-free food.
A prepared food that doesn't have an ingredient that contains gluten.
Food that has not been cross-contaminated with ingredients that have gluten during production.
Food with a gluten-containing ingredient that has been processed to remove gluten. The food needs to have less than 20 parts per million of gluten after the removal process.

Alcoholic drinks made from naturally gluten-free ingredients, such as grapes or juniper berries, can be labeled gluten-free. Wine, distilled liquor and fruit cider that's made without barley malt are examples of drinks that don't have gluten.

Beer, ale and other malted drinks made with barley have gluten in them. They're not safe to drink if you're on a gluten-free diet. Some mixed alcoholic drinks have gluten in them as well. So it's important to find out what ingredients they're made with before drinking. Alcoholic drinks that are labeled gluten-free are OK to drink. But those labeled "gluten removed" or "processed to remove gluten" are not safe for people with celiac disease.

Processed foods that often have gluten in them

If you follow a gluten-free diet, it's important to read labels of processed foods. This helps you find out if the foods have wheat, barley or rye in them.

In general, be careful of the following processed foods if you're on a gluten-free diet. Keep in mind that foods labeled as gluten-free or made with gluten-free grain are OK to eat.

Starchy foods that often have gluten in them include:

Breads.
Bulgur wheat.
Cereals.
Communion wafers.
Croutons.
Matzo.
Pastas.
Seasoned rice mixes and pilafs.

Processed sweets and snacks that often have gluten in them include:

Cakes and pies.
Candies.
Cookies and crackers.
French fries.
Seasoned snack foods, such as potato and tortilla chips.
Soups, soup bases, broth, bouillon or soup mixes.

Alcoholic drinks and related processed items that often have gluten in them include:

Beer, ale, porter, stout.
Malt, malt flavoring and other malt products.

Processed meats that may have gluten in them include:

Burgers.
Hot dogs.
Imitation seafood.
Meat loaf.
Processed lunchmeats.
Sausage.

Condiments that may have gluten in them include:

Gravies.
Salad dressings.
Sauces, including soy sauce.

Medicines and supplements

Medicines may use wheat gluten as a binding agent. Talk with your healthcare professional or pharmacist about the medicines you're taking. Dietary supplements that contain wheat gluten must have "wheat" stated on the label.

Eating gluten-free at home and in restaurants

For people with celiac disease, in particular, it's important not to eat gluten or use medicines with gluten in them. The following tips can help you keep gluten from accidentally getting into the food you make at home:

Store gluten-free foods in a different place from where you store foods that have gluten.
Keep cooking surfaces and food storage areas clean to remove any ingredient that has gluten in it.
Wash dishes and cooking equipment thoroughly.
Use separate cutting boards, cooking equipment and utensils for gluten-free foods. For instance, you could think about buying a separate toaster or toasting bread in the oven. This lowers the risk of cross-contamination from crumbs that could have gluten in them.

You also can take steps to lower your chances of being exposed to gluten when you eat out. Use these tips:

Read restaurant menus online ahead of time if you can to be sure there are options for you.
Eat out early or late when a restaurant is less busy and better able to address your needs.
Ask your server what seasonings will be used and how the food will be prepared and handled. Also ask if your food can be made with separate, well-cleaned equipment and surfaces.

Results

If you have celiac disease, it's important to follow a strict gluten-free diet for life. People who follow the diet and prevent cross-contamination have fewer symptoms of the disease. They're also less likely to have health problems that stem from damage to the small intestine.

It's not clear if non-celiac gluten sensitivity is a life-long condition. Some research suggests that you may follow the diet for 1 to 2 years. Then you get tested again to see if you're still sensitive to gluten.

Some studies have looked at the benefits that people without celiac disease or non-celiac gluten sensitivity think they get from the gluten-free diet. More research is needed to find out whether science can support any of the following claims about the diet's results:

Weight loss.
Overall improved health.
Better gut health.
Improved athletic performance.

Risks

The foods not included in a gluten-free diet provide important vitamins and other nutrients. For example, whole-grain breads and other products are natural or enriched sources of the following:

Iron.
Calcium.
Fiber.
Thiamin.
Riboflavin.
Niacin.
Folate.

So, following a gluten-free diet likely will change the nutrients you get from food. Gluten-free breads and cereals have varied nutrient levels compared with the products they are replacing.

Some gluten-free foods also have higher fat and sugar contents than the gluten-rich food being replaced. It's important to read labels, not only for gluten content but also for overall nutrient levels, sodium, and calories from fats and sugars.

You can talk with your healthcare professional or dietitian about what nutrients you may need more of. Then ask what foods are good sources of the nutrients you need.

Costs

The costs of prepared gluten-free foods tend to be higher than the cost of the foods being replaced. The expense of following a gluten-free diet can be large, especially if your diet includes foods that aren't naturally gluten-free.