What is a Soy Allergy?

A soy allergy is an adverse response or overreaction of the body’s immune system to the proteins in soy or products that contain soy. When soy is eaten, the body sees the proteins from soy as a foreign invader, sending out chemicals to defend against it. Those chemicals are what cause the symptoms of an allergic reaction.

👥 How common is it?

Soy allergy is a common allergy found in children, and while most people will grow out of this by adulthood, some people do not. Typically this allergy will start in infancy. Symptom onset ranges from a few minutes to a few hours after consuming the allergen.

🌱 What is soy?

Soy, also known as soya, is the product of soybeans, a legume that is widely grown and used for its high protein content and high versatility in foods.


Symptoms of Soy Allergy

An allergic reaction to soy can bring on many symptoms. These include hives or a skin rash; nausea, stomach cramps, vomiting and/or diarrhoea; stuffy or runny nose, headaches, and asthma.

🚑 Anaphylaxis

Although less common, some allergy sufferers are also at risk of having a potentially life-threatening anaphylaxis reaction. In extreme cases there could be a dramatic fall in blood pressure, the person may become weak and floppy, and may have a sense of something terrible is happening. This may lead to collapse and unconsciousness. On rare occasions, death can occur.

It is important to be able to recognize and manage reactions quickly in order to prevent serious health consequences. The first line of action for anaphylaxis is the timely use of epinephrine which is available by prescription in a self-injectable device.

Symptoms of an allergic reaction to food

If you are concerned that you or your child may have an allergy, you should consult with a medical professional or a Registered Nutritionist or Dietitian. If your child is diagnosed with an allergy, it’s important to inform all people involved in the child’s care. This includes their nursery, school, and after-school clubs, as well as grandparents, relatives, and the parents of their school friends.

Managing a Soy Allergy

🛒 Store bought food

Avoiding soy can be a challenge since it is present in many non-suspect foods like meat products, bakery goods, chocolate and breakfast cereals. Having a soy allergy means avoiding products that are based on, or contain soy. Therefore, it’s important to always read the label.

As soy is one of the top food allergens in the USA and UK, it’s presence must always be declared on product the labels of any food product it’s in. This makes it easier to avoid.


❌ Foods to avoid

Soy-based foods or alternative names for soy include: Soy milk and yogurt, tofu or tempeh, Soy sauce, shoyu, or tamari, Miso, Edamame, Glycine max

Other foods or terms that indicate or may indicate the presence of soy: Textured vegetable protein (TVP), Hydrolyzed vegetable protein, Monodiglyceride, Monosodium glutamate (MSG).

❓Products that may be tolerated by people with a soy allergy

Most people with a soy allergy can consume highly refined soybean oil as during the processing  the soy proteins responsible for allergic reaction, is rapidly reduced in concentration.

Soy lecithin is another ingredient derived from soybeans. It is typically used as an emulsifier (to keep oil and water from separating) in many foods and research has shown people with a soy allergy can tolerate this. It’s important to note that opinion is still divided on the level of risk posed by soy lecithin, with the UK considering it a risk, while the USA does not.

❗️It is advised to always ask your health practitioner before consuming any of  these products as people’s sensitivity will vary.


✅ What replacements can I use?

There are many replacements for soy-based foods. For a drink replacement, try dairy milk or nut-based products like almond or hazelnut milk, coconut milk, oat milk and even hemp milk. However it should be noted that some of these do not match the protein content of soy.

Soy sauce, tamari, and miso are often used in dishes to give an ‘umami’ flavour. Coconut Liquid Aminos are a great alternative and can be used in the same way as soy sauce or tamari. Be aware that many other types of liquid aminos are made using soy, so always check the labels first.

Soy products are often seen as a go-to source of protein for many people following a vegan or vegetarian diet. However, those who cannot tolerate soy, must find alternative protein sources. Seitan, for example, is a wheat gluten product that can be used as a good plant-based protein alternative to  tofu.

Beans are also a great protein source for meals and are a source of fibre. It’s important to eat both cereal and legume sources of protein as they each give complementary amino acid profiles that are essential for adequate nutrition. A good example of combining these two in one meal would be beans (legume) on toast (cereal).


Please note: This Spoon Guru Fact Sheet should be used as a source of information only. It should not be used as a replacement to nutritional advice from an accredited medical professional.

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