Soy Allergy – Everything you need to know

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Did you or your child recently get diagnosed with a soy allergy? Are you feeling anxious or overwhelmed and like you’re not even sure where to begin? 

If that sounds like you, keep reading! Below you’ll find everything you need to know about soy allergies. I’ve included symptoms to look for, foods to avoid, extra information about hidden names for soy, and even tips for how to manage allergies at home.

soybeans in a bowl over a blue background.

What Is A Soy Allergy?

Soy allergy is a type of food allergy that occurs when your immune system mistakenly triggers a defensive response to soy, leading to reaction symptoms that can be mild or very severe. Infants and young children are more likely to have soy allergies than adults. Most children outgrow a soy allergy by age 10.

What is Soy?

Soybeans are a high-protein legume native to East Asia but are now cultivated and consumed across the world. Soybean seeds have a tiny dark spot and are most often a pale yellow color. The immature soybeans that are harvested when green are called edamame.

Soy Allergy Symptoms and Reactions

Symptoms and reactions can vary greatly between people. Most reactions are mild, but in some cases, they can be severe and life-threatening. 

Some mild symptoms are:

  • Tingling
  • Hives or skin rash
  • Swelling of the lips or mouth
  • Wheezing
  • Coughing
  • Diarrhea
  • Cramps and abdominal pain
  • Vomiting
  • Nausea

More severe symptoms include:

  • Trouble breathing
  • Chest pain
  • Drop in blood pressure
  • Dizziness or lightheadedness
  • Loss of consciousness 

These more severe reactions may actually be symptoms of anaphylaxis and should be treated immediately. 


Anaphylaxis is a potentially life-threatening reaction to an allergy attack. It can impair breathing, cause a sudden drop in blood pressure, and send the body into complete shock. 

If you have a soy allergy, most likely, your doctor will prescribe an EpiPen, which can be used to combat anaphylaxis. To know more about this severe allergic reaction, check out my post about What Is Anaphylaxis and How Is Treated.

What Causes A Soy Allergy?

A soy allergy is caused by your immune system overreacting to the proteins found in soy. Any time your body is exposed to soy proteins, it triggers your immune system to react. The immune system releases chemicals called histamines which cause symptoms and reactions.

eggless turtle cake

Baking with food allergies does not need to be frustrating! Even if you can’t use certain ingredients, you can produce amazing desserts that the whole family will love.

Intolerance or Allergy?

With a soy allergy, your immune system treats the proteins found in soy as a foreign invaders and overreacts. With an intolerance, your digestive system can’t break down the proteins, and you may experience gas, bloating, or diarrhea.

If you feel sick after eating Asian food or drinking soy milk you may need to consult your doctor. Your healthcare provider can conduct tests to confirm a soy allergy or intolerance and prescribe medications.

Soy Allergy Treatment

Strict avoidance of soy is recommended to prevent a reaction. Unfortunately, there is no treatment right now that cures food allergies. Researchers are now studying ways to go beyond today’s methods of treating allergies. Hopefully, we may soon have better and new ways to block the body’s allergic response. 

Once your doctor has confirmed a soy allergy, you will most likely get a prescription for self-injectable epinephrine in case of a severe reaction happens, and an antihistamine for mild reactions.

Managing Soy Allergy

The best way to manage allergies at home is to completely avoid bringing soy or soy byproducts into the house. You should always read labels, inform family members, and have a system set in place in case of an allergy attack.

If avoiding soy altogether isn’t possible, you can reduce the risk of cross-contamination by color-coding food in the fridge with red and green containers, having an allergy-safe shelf in the pantry where safe foods are stored, and having an “In Case Of Emergency” action list on the fridge. Check out my 8 Tips to Keeping an Allergy Friendly Kitchen.

Also, be super careful when eating out, always read labels, and keep your emergency kit close. 

Common Foods That Contain Soy

In order to prevent an allergy attack, it is always important to thoroughly read ingredient labels. In the United States, soybeans are one of the nine recognized allergens, and companies are required to label products clearly if they contain soy. 

Common foods that contain soy are:

  • Edamame
  • Miso
  • Soy-based non-dairy items such as milk, ice cream, yogurt, and cheeses
  • Soy protein
  • Soy sauce
  • Tamari
  • Teriyaki sauce
  • Tofu

These foods may also contain soy, so it’s important to take caution:

  • Baked goods
  • Canned soup
  • Cereals
  • Frozen dinners
  • Low-fat peanut butter
  • Protein bars
  • Infant formula and baby food
  • Processed meats
  • Salad dressing
  • Worcestershire sauce

Ingredients To Avoid

If you’re reading ingredient labels to prevent accidental ingestion, it’s important also to be aware of other names for soy. Look out for:

  • Glycine max
  • Hydrolyzed soy protein
  • Soy protein
  • Vegetable protein
  • Mono-diglyceride
  • Monosodium glutamate (MSG)

Soy Oil and Soy Lecithin

Soy oil and soy lecithin are highly refined byproducts and are not required to be labeled as an allergen. There are studies that show that many people with a soy allergy can safely consume highly refined soy oil and soy lecithin.

However, it is ALWAYS a good idea to check with your doctor to see if you should avoid those products.

Soy and Eggs

Many commercially grown eggs are found to contain soy proteins since soy has become a popular ingredient in animal feed because it is a cheap protein that promotes quick growth and efficient egg production. If you want to eat eggs, I suggest buying them from a local farmer’s market. Pasture-raised eggs are soy-free.

Will My Child Outgrow Their Allergy?

There’s no guarantee that your child will outgrow their soy allergy, but studies have shown that some kids outgrow soy allergy by age three. However, the majority of those children affected outgrow it by age ten. 

Frequently Asked Questions

What foods is soy hidden in?

Soy is found in many processed foods, so you must be very careful. Soy is especially tricky to avoid because it is often found in unexpected places, such as infant formulas, canned broths, soups, canned tuna, processed meats and hot dogs, energy bars, baked goods, Asian cuisine, chicken nuggets, low-fat peanut butter, alternative nut butter, and even vodka.

Who does a soy allergy affect?

Soy allergies mostly affect infants and children under the age of 4. Most kids outgrow their allergies, so it’s rare (but not impossible) for an adult to be allergic to soy.

Can you develop a soy allergy?

Soy allergy mostly affects infants and children under the age of 4. However, anyone at any age can suddenly develop an allergy to soy. 

How common is soy allergy?

It is estimated to affect about 0.3% of the population, with the majority of those affected being children and infants. Soy is one of the none allergens recognized by the FDA.

Can you eat eggs with a soy allergy?

Many commercially grown eggs are found to contain soy proteins since soy has become a popular ingredient in animal feed because it is a cheap protein that promotes quick growth and efficient egg production. If you want to eat eggs, I suggest buying them from a local farmer’s market. Pasture-raised eggs are soy-free.

While a soy allergy may be a hard diagnosis to deal with at first, there are steps you can take to stay safe. You may feel lost, anxious, overwhelmed, or maybe even angry, but those are all normal reactions.

Living with a food allergy is totally manageable! Yes, it requires attention to detail, planning, and vigilance. It also means that certain foods must come out of your diet. But it does not mean that life as you know it will end. With some simple safety steps, you can still eat out, travel, go to parties, send your child to school or on play dates, and live a normal life. 

If you’re looking for support, I suggest you join a Facebook group, find a blog, or listen to a podcast. These places are full of overwhelming support and a vast amount of information. It’s going to be difficult at first, I’m not going to lie, but I have faith that you’re strong enough to overcome this diagnosis.

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