Oats are healthful and gluten-free. They provide fiber and protein, and they can be suitable for people with celiac disease. However, some people may experience reactions to oat protein.

Celiac disease is an autoimmune disorder that damages the small intestine, reducing its ability to absorb nutrients.

Celiac disease demands a gluten-free diet. However, many other people without the disease choose to avoid gluten in the hope that it will help them lose weight, fight perceived food intolerances, and improve overall health.

Between 2009-2014, the number of Americans eating gluten-free diets tripled. About 1 in 133 Americans, or less than 1 percent, has celiac disease.

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While oats do not contain gluten, there are a few reasons why people concerned about gluten intolerance should be wary.

Gluten is a protein found in wheat, rye, barley, and triticale. Oats do not belong to any of these groups; so people with gluten intolerance do not usually have to worry about gluten in uncontaminated oats. However, there are several concerns about oat consumption.

People with gluten intolerance, particularly those with celiac disease, may still need to be careful about eating oats. One reason is that they can easily be contaminated with gluten, because they may have been grown in fields near wheat and other gluten-containing crops.

Additionally, many oat-processing plants also process foods that contain gluten. People with gluten intolerances should always check food labels, and look for oats that are completely free of gluten.

Avenin sensitivity and oats

Oats do not have to be contaminated to be a problem, however. Some people with celiac disease relapse after eating oats, even on an otherwise gluten-free diet.

The culprit is likely to be avenin, a protein in oats that plays a role similar to gluten in wheat. In some people with celiac disease, avenin activates the same immune cells that react to gluten.

A recent study showed that eating 100 grams (g) of oats a day for 3 days activated immune cells that targeted avenin, but only in 8 percent of participants.

Additionally, many participants reported digestive symptoms, but this was not related to immune cell activation. Their reaction could have been due to a "nocebo" effect - similar to a placebo, but producing harm. It could also have been because participants ate double the recommended daily serving size.

A further finding of the study was an increased immune cell reaction in people who ate barley prior to the 3-day oat study, though researchers were unsure why.

The study's authors concluded that smaller quantities of oats are probably fine for people with celiac disease.

The North American Society for the Study of Celiac Disease recommend monitoring anti-tTG (anti-tissue translutaminaste) antibody levels before and after adding oats to the diet. This gives clear data about how eating oats affects a person.

People who try oats should start with small quantities and log any symptoms they experience. If no symptoms occur, and blood level antibodies remain stable, it should be safe to keep eating oats.

Oats offer many nutritional benefits, which people who avoid gluten might not get elsewhere in their diet.

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Oats are a whole grain, rich in fiber, and contain many nutrients.

So, it is worth considering the following:

  • Oats are a whole grain. Whole grains are linked to a reduced risk of heart disease. They may also lower the risk of having a stroke.
  • Oats are rich in fiber. Fiber supports the health of the stomach and intestines by easing constipation. Fiber also supports feelings of fullness, reducing the desire to overeat. Reducing food intake can lower the risk of obesity and the many diseases that can accompany it. Fiber can also help lower blood sugar so is helpful for gluten-intolerant people with diabetes.
  • Oats are high in several nutrients. They offer 191 percent of the recommended daily intake (RDI) of manganese, 41 percent of phosphorous, 34 percent of magnesium, 24 percent of copper, and 20 percent of zinc. They also offer 11 percent of the RDI of folate, which pregnant women should consume to protect their babies from certain disorders.
  • Oats are rich in antioxidants. Oats contain a group of antioxidants called avenanthramides, which are found almost exclusively in oats. Avenathramides may lower blood pressure by helping the body produce more nitric oxide.
  • Oats reduce total cholesterol. Oats also reduce LDL cholesterol, the "bad" cholesterol that can contribute to heart disease.

When do oats pose a health concern?

Some diets, including many forms of the Paleo diet, recommend avoiding oatmeal. No evidence supports the notion that oatmeal is dangerous for people without an allergy or intolerance to its components.

People with gluten sensitivity who do not have celiac disease may also worry about eating oatmeal. Some research suggests any reaction is not a reaction to gluten. Instead, the problem is a group of foods, collectively known as FODMAPs.

FODMAPs are a group of carbohydrates, including lactose and fructose that some people struggle to digest. Many gluten-containing foods also contain FODMAPs, but gluten and FODMAPs are distinct. Gluten is a protein while FODMAPs are carbohydrates.

Gluten contamination should not affect the overall FODMAP level of oats, so oats processed with gluten-containing products are usually fine to eat. However, different types of oats have different FODMAP levels, so people who are sensitive to FODMAPs should discuss oatmeal intake with their doctor and dietitian.

Like many healthful foods, oats can lose their benefits when layered with add-ons such as brown sugar. Brown sugar can make oatmeal taste sweeter, but it is high in calories and can elevate blood sugar levels.

For flavorful oatmeal that is good for people with a variety of health needs, try adding chopped walnuts and dried fruit. Cinnamon adds even more flavor, and yogurt offers creaminess that packs a protein-filled punch.

Using oats that have been soaked overnight offers nutrient-dense oat options that individuals can tailor to their specific tastes. Lots of varieties are available, so add or remove ingredients according to taste and dietary needs.

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Overnight oats can be a healthful and delicious breakfast.

Here's one classic example:

  1. Begin with 1/3 cup rolled oats, and add 1/3/-1/2 cup milk (or almond or soy milk).
  2. Add 1/3 cup plain Greek yogurt (not sweetened yogurt), which boosts the protein content.
  3. Add a small chopped banana or 1 cup of fresh fruit.
  4. Sprinkle a teaspoon of chia seeds on top.
  5. Add cinnamon to taste.
  6. Leave overnight.
  7. In the morning, top with nuts, such as walnuts or almonds.

Foods rich in oats can also contain other grains, including those that may activate a celiac immune reaction.

People with celiac and other gluten sensitivities should read ingredient lists carefully and check the packet to see how the food was processed. If the product was processed alongside gluten-containing ingredients, avoid it.