How to know if a food has gluten

Consumers often have questions about How to know if a food has gluten and how and who should follow a gluten-free diet. Let's clarify all doubts on this topic.

There is currently a strong association between the claim “gluten-free” and the practice of a healthy diet, leading to an increase in sales of this type of product in large food distribution chains and inevitably making gluten-free diets a “fad”.

However, it is important to emphasize that gluten-free diets are essentially intended for people diagnosed with Celiac Disease – an intestinal disease caused by permanent sensitivity to gluten.

Learn how to identify if a food contains gluten

What is gluten?

Gluten is the protein part of the wheat, rye, oat and barley grains that gives the flour enough viscoelasticity to be transformed into bread.

Gluten is not an isolated protein, but rather a mixture of several proteins – gliadins and glutenins. Gliadins are the component that triggers the disease in genetically predisposed individuals.

Now that we know what gluten is, let's move on to the question that brings you here: how to know if a food contains gluten.

How to check if a product contains gluten

Portuguese legislation requires that all packaged products indicate their composition on the label so that it is possible to know whether a food contains gluten.

By law, all packaged foods that contain substances or products containing gluten must be clearly referenced in the list of ingredients using spelling that clearly distinguishes them from other ingredients.

They are usually found in a more intense shaded color or even underlined. In addition to this distinction in the list of ingredients, the presence of gluten can be identified by the phrase “Contains gluten” or “May contain gluten”.

On the other hand, if a packaged food is certified as gluten-free, it can be identified by the presence of the symbol to that effect.

How to do a gluten-free diet

Following a gluten-free diet can be challenging, but there are several alternatives. Foods such as quinoa, rice, tapioca, corn, potatoes, buckwheat, teff and amaranth are some examples.

When it comes to oats, there is some controversy, and they should only be consumed if the packaging is certified as gluten-free.

Some studies indicate that oats contain gluten, but others claim the opposite, suggesting that they are safe to eat. However, oats are often grown in the same fields and processed in the same machines as other grains, such as wheat or rye, and cross-contamination can occur. 

For this reason, in Portugal, oats are considered a food that contains gluten. With the naked eye, the only way to see if there is gluten in a food is to wash the pasta in running water until all the starch is gone – the elastic substance that remains after this process is called gluten.

Is it healthy to follow a gluten-free diet?

A gluten-free diet is important for anyone suffering from any type of pathology that affects the intestinal mucosa, and it is always advisable to make this change therapeutically.

Now that you know what gluten is and how to know if a food contains gluten, don't forget to look at the labels carefully.

If you experience symptoms associated with the consumption of foods containing gluten, you should seek out a specialist such as your family doctor or nutritionist.