Soy is a healthy and versatile ingredient that can be used in many different dishes. However, some people may experience soy allergy symptoms, such as itching, swelling, difficulty breathing, and more.

If you think you may be allergic to soy, it is important to avoid soy-based products. Keep reading to learn more about soy allergies, why they occur, how to go about them, and healthy alternatives to consider.

Also check out: Is Soy Gluten Free, Vegan Protein Sources, 8 Health Benefits of Tofu, and How to Grow Edamame.

What Is Soy?

Soy is a plant that is native to East Asia. It is a member of the legume family, which includes beans, peas, and lentils. Soy is a versatile crop that can be used for food, animal feed, and fuel.

It’s a good source of protein and contains all the essential amino acids our bodies need. It is also low in saturated fat and high in fiber.

Additionally, soybeans are a good source of vitamins and minerals, such as iron, calcium, and magnesium.

Consuming it regularly can help lower cholesterol levels, improve bone health, and reduce the risk of certain types of cancer. It’s also a great meat alternative in many vegan and vegetarian dishes.

Forms of Soy

There are many different types of soy products available on the market today. Some of the most popular include:

Tofu – Tofu is made from soybean curds that have been pressed into solid blocks. It is a versatile ingredient that can be used in savory or sweet dishes.

Soy Milk – Soy milk is made by soaking soybeans and grinding them with water. It is a dairy-free alternative to cow’s milk that is rich in protein and calcium.

Tempeh – Tempeh is made from fermented soybeans that have been formed into a cake-like substance. It has a slightly nutty flavor and can be used as a meat replacement in recipes.

Edamame – Edamame is a type of soybean that is popular in Japanese cuisine. It is often served as a side dish or appetizer, and can be found in many Japanese restaurants.

Edamame is high in protein and fiber, and low in fat. It is also a good source of vitamins and minerals, including iron, calcium, and magnesium.

Soy products: soy beans, soy milk, tofu and soya chunks isolated on white background, top view

What Is a Soy Allergy?

Most people with a soy allergy are allergic to the proteins in soybeans. This occurs when the body’s immune system mistakenly identifies soy proteins as harmful.

When someone with a soy allergy eats something containing soy proteins, their immune system reacts by releasing histamine and other chemicals into the bloodstream.

This can cause symptoms such as hives, itching, swelling, and difficulty breathing. In severe cases, anaphylaxis can occur. Anaphylaxis is a potentially life-threatening reaction that can cause shock and respiratory failure.

Soy Allergy Symptoms

Skin reactions

  • Hives
  • Itching
  • Swelling

Gastrointestinal symptoms

  • Nausea
  • Vomiting
  • Abdominal pain
  • Diarrhea

Respiratory issues

  • Wheezing
  • Difficult breathing
  • Anaphylactic shock

Soy Allergy Testing and Diagnosis

If you think you may be allergic to soy, it’s important to get tested by an allergist.

Soy allergy testing can help confirm whether or not you’re allergic to soy and, if so, how severe your allergy is.

Skin prick tests

Skin prick tests involve placing a drop of soy protein on your skin and then making a small scratch on the surface to allow the liquid to get into the skin. If you’re allergic to soy, you’ll usually develop a raised, itchy bump within 15 minutes.

Blood tests

Blood tests are less common, but they can be used to confirm the results of a skin prick test. They involve taking a sample of your blood and then testing it for the presence of soy antibodies.

If you’re found to be allergic to soy, the best way to avoid a reaction is to avoid all foods that contain soy protein. However, some people with mild allergies may be able to tolerate small amounts of soy in their diet. Talk to your allergist about what’s right for you.

Intradermal skin test

An intradermal skin test is almost similar to the skin prick test; however, unlike the skin prick, it involves injecting the allergen under the skin on your arm. If you’re allergic to the allergen, you’ll develop a raised, itchy bump within 15 minutes.

Food challenge test

If you suspect that you may be allergic to soy, your doctor may recommend a food challenge test.

This involves eating small amounts of soy-containing foods under medical supervision to see if you have a reaction.

The food challenge test is the most accurate way to diagnose a soy allergy. It is generally safe and well tolerated, but there is a small risk of having a severe reaction.

How to Test For Soy Allergy At Home

Consider an elimination diet

If you think you may have a soy allergy, the best way to find out is to do an elimination diet. This means completely removing soy from your diet for a period of time (at least two weeks, and preferably four weeks), then slowly reintroducing it and seeing how your body reacts.

An elimination diet can be tricky because soy is in so many foods. But with a bit of planning, it’s definitely doable.

Here are some tips:

  1. Check ingredient labels carefully. Soy can hide under many names, including “vegetable protein,” “hydrolyzed vegetable protein,” “textured vegetable protein,” and more.
  2. Avoid processed foods as much as possible. Many processed foods contain soy, even if it’s not listed on the label.
  3. Stick with whole, unprocessed foods as much as possible. This includes fresh fruits, vegetables, and grains.
  4. Ask questions when dining out. Many restaurants use soy-based products, so it’s important to ask about ingredients and cooking methods when ordering food.
  5. Be prepared with alternative ingredients. If you’re used to cooking with soy sauce or tofu, you’ll need to find new ingredients to use during this period.
Perform a skin prick test

If you think you may have a soy allergy, you can also do a skin prick test at home to find out. All you need is a skin prick kit, which you can purchase at your local pharmacy or online. Next, you need to follow the instructions given.

Whichever results you get, it’s always important to get a confirmatory test from a professional.

Common non-soy food products that may contain soy

If you have a soy allergy, you need to be careful about the foods you eat since soy is present in many products. Here are some common non-soy foods that may contain soy:

1. Salad dressings and sauces

When it comes to salad dressings and sauces, be sure to check the labels carefully. Many popular dressings and sauces contain soybean oil or soy sauce.

Opt for dressings and sauces made with olive oil or another type of oil. Also, be on the lookout for tahini, which is made from ground sesame seeds and olive oil but may sometimes contain soy.

 2. Bread and baked goods

Many of these products contain soy flour or soybean oil, which can be a hidden source of soy. Soy can also be common in gluten-free labeled products. So, be sure to check the ingredient label carefully before purchasing or consuming any bread or baked goods.

3. Breakfast cereals

If you’re looking for a soy-free breakfast option, you may want to avoid certain cereals. Some popular cereal brands may contain soy in the form of soy flour or soy lecithin.

Others may be made with wheat that has been contaminated with soy during processing. To be safe, check the ingredient list on your cereal box or package. There are plenty of delicious soy-free cereals out there, so you’re sure to find one that you love!

4. Snacks

There are a few common snacks that may contain soy without you realizing it.

Be sure to check labels carefully before purchasing or consuming any of the following:

  • Granola bars: Many store-bought granola bars contain soy protein or soy lecithin.
  • Cereal: Some cereals, especially those marketed as healthy or natural, can contain soy in the form of soy flour or isolated soy protein.
  • Protein bars and shakes: These popular on-the-go snacks often contain soy protein isolate or concentrate.
  • Cookies and crackers: You may be surprised that some cookies and crackers contain soybean oil or soy flour.
  • Others: Other snack foods such as chips, popcorn, and pretzels may also contain small amounts of soy lecithin, an additive that helps keep these products from sticking together. While lecithin is generally considered safe, it’s best to avoid foods containing this ingredient if you have a soy allergy.
5. Meat alternatives

Most plant-based meat substitutes are soy-derived, including tofu, tempeh, and even textured vegetable protein (TVP).

However, there’re other (although limited) soy-free alternatives, including:

Seitan: Seitan is a wheat-based, soy-free meat alternative that has been popular in Asia for centuries. It is made from the gluten of wheat flour and has a chewy, meat-like texture.

Seitan is high in protein and low in fat, making it a healthy option for those looking for a meat-free diet.

Quorn: Quorn is a meat-free brand of products made from mycoprotein, which is a type of fungi. It’s high in protein and fiber and low in fat, making it a healthy option for those looking to reduce their meat intake.

However, some Quorn products contains egg whites, so they are unsuitable for vegans or those with egg allergies.

Assortment of soy products on wooden background

How Long Can a Soy Allergy Last?

Soy allergies are often first diagnosed in infancy or early childhood but can develop at any age. They can also last for a long time, even a lifetime.

While some people outgrow their allergy, others may experience symptoms their entire lives. The severity of symptoms can range from mild to life-threatening.

Some people may be able to eat small amounts of soy without having any reaction, but it’s best to stay on the side of caution.

There is no cure for soy allergy, so avoiding soy entirely is the best way to prevent reactions.

How Is Soy Allergy Treated?

If you have a mild reaction, you may be able to treat it at home with over-the-counter antihistamines and/or topical corticosteroids.

For a more severe reaction, you will likely need to go to the emergency room for treatment with injectable epinephrine and/or IV steroids.

If you have a soy allergy, it is important to carry an epinephrine auto-injector with you at all times in case of accidental exposure.

You should also make sure that your family and close friends know about your allergy and how to use your auto-injector in case of an emergency

Soy Allergy Vs. Soy Intolerance

There is a lot of confusion surrounding soy allergy and soy intolerance. People often mistake one for the other when, in reality, they are two very different things.

Soy allergy is a true food allergy that’s caused by an immune reaction to soy proteins. This can lead to severe symptoms such as anaphylaxis, which can be life-threatening.

On the other hand, soy intolerance is not an allergic reaction but rather a digestive problem that can cause gas, bloating, and diarrhea.

While soy allergy is relatively rare, affecting only about 0.4% of the population, soy intolerance is much more common.

It is estimated that up to 15% of people may be sensitive to soy. If you think you may have a soy allergy or intolerance, it’s important to see a doctor for a proper diagnosis.

Treatment for soy allergy typically involves avoiding all soy products. For soy intolerance, dietary changes may be enough to manage symptoms.

Final Thoughts

Soy is a type of legume that is native to East Asia. It is a key ingredient in many Asian cuisines, as well as being used in animal feed and some industrial products.

People who are allergic to soy may experience a range of symptoms, including skin rashes, hives, nausea, vomiting, and difficulty breathing. In severe cases, soy allergy can lead to anaphylaxis, a potentially life-threatening condition.

There is no cure for soy allergy, and avoiding soy products entirely is the only way to prevent reactions.

This can be a challenge for people with severe allergies, as soy is found in many common foods and products.

However, with careful planning and avoidance of known triggers, it is possible to manage soy allergy symptoms and live a normal, healthy life.

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