What Is Tofu?

Tofu, also known as bean curd, is made by coagulating soy milk, pressing the curds into solid blocks, and cooling it.

There are several varieties of this popular food. Some of the most common include:

• Extra-firm. A dense type of tofu that's best suited for hearty dishes like stir-fries or chilis.

• Firm. The most versatile variety that can be used for grilling, broiling, or scrambles.

• Soft/silken. A great alternative to dairy and eggs that can be blended into smoothies or used in desserts.

• Prepared. A convenient and ready-to-eat tofu that's usually flavored and can easily be added to salads or sandwiches.

Tofu is often eaten as a plant-based alternative to meats and other animal proteins and is common in vegetarian and vegan diets (1).

It's considered a low-calorie, high-protein food. A 3-ounce (85-gram) serving provides 70 calories and 8 grams of protein (2).

It's also a good source of certain nutrients, including the minerals copper, phosphorus, and magnesium.

Not to mention, tofu contains all nine essential amino acids your body needs, making it a complete protein (3).

Summary

Tofu is made from soy and often used as a replacement for animal protein. It's an excellent source of protein and several important nutrients, yet low in calories.

Plain Varieties Are Usually Gluten-Free

Gluten is a protein found in wheat, barley, and rye.

Some people can't eat gluten due to celiac disease or non-celiac gluten sensitivity and must follow a gluten-free diet to avoid adverse health effects (4, 5).

For the most part, plain, unflavored tofu is gluten-free.

Ingredients can vary between brands, but plain tofu usually contains soybeans, water, and a coagulating agent like calcium chloride, calcium sulfate, or magnesium sulfate (nigari).

All of these ingredients are gluten-free. However, certain varieties may contain gluten, so it's best to read the ingredient label if you're trying to avoid it.

Summary

People with celiac disease or non-celiac gluten sensitivity can't tolerate gluten and need to follow a gluten-free diet. Plain, unflavored tofu is typically gluten-free.

Certain Varieties Contain Gluten

While plain tofu is often gluten-free, some varieties may contain gluten.

Can Be Cross-Contaminated

Tofu can become cross-contaminated with gluten in several different ways, including:

• at the farm
• during processing
• during manufacturing
• at home when cooking
• at restaurants

Tofu is sometimes processed or manufactured in the same facilities as wheat or other gluten-containing ingredients. If equipment is not properly cleaned, it could be contaminated with gluten.

Many brands are certified gluten-free, meaning that a third party has verified the product's gluten-free claim.

For those who are intolerant to gluten or have celiac disease, choosing certified gluten-free tofu may be the safest choice.

Ingredients May Contain Gluten

Some tofu varieties are already prepared or flavored.

Popular flavors of tofu include teriyaki, sesame, stir-fry, spicy orange and chipotle.

Often, these flavored varieties contain soy sauce, which is made from water, wheat, soybeans, and salt (2).

Therefore, flavored or marinated tofu that contains soy sauce or other wheat ingredients is not gluten-free.

However, there are some flavored varieties of tofu that contain tamari instead—a gluten-free version of soy sauce.

Summary

Tofu can come into contact with gluten during processing or manufacturing. Also, flavored varieties that contain soy sauce or other wheat-based ingredients are not gluten-free.

How to Make Sure Your Tofu Is Gluten-Free

You can take a few steps to ensure the tofu you're eating is gluten-free.

Check the ingredients, especially if buying a flavored or marinated variety. Make sure it has no wheat, barley, rye, or other gluten-containing ingredients, such as malt vinegar, brewer's yeast, or wheat flour.

See if the tofu is marked as "gluten-free" or "gluten-free certified."

According to the Food and Drug Administration (FDA) guidelines, food manufacturers can only use the label "gluten-free" if the gluten content is less than 20 parts per million (ppm).

This is the lowest level that can be found in foods using scientific testing. Additionally, most people with celiac disease or non-celiac gluten sensitivity can tolerate these very small amounts (6).

Still, a small number of people with celiac disease are sensitive to even tiny amounts. For people who are sensitive to gluten, certified gluten-free tofu is the safest choice (7).

Avoid tofu labeled as "may contain gluten" or "made or shared equipment with wheat/gluten," as it may contain more than the FDA limit for labeling items gluten-free.

Gluten-free brands include:

• House Foods Tofu
• Morinaga Nutritional Foods, which produces Mori-Nu Tofu
• Nasoya Tofu

However, be aware that these brands also produce varieties that are flavored or marinated with soy sauce, which contains gluten.

Summary

To ensure tofu is gluten-free, check the nutrition label to make sure it doesn't list soy sauce or other gluten-containing ingredients. Also, look for packages that say "gluten-free" or gluten-free certified."

The Bottom Line

Plain tofu is generally gluten-free, but flavored varieties may contain glutenous ingredients, such as wheat-based soy sauce.

Plus, tofu may become cross-contaminated during processing or preparation. If you avoid gluten, find tofu that is certified gluten-free and doesn't contain glutenous ingredients.