Top 9 Food Allergens Explained: Symptoms, Conditions, and Safe Alternatives

Andrea Hardy, RD

Food allergies are more common than many people realize, affecting an estimated 33 million people in the USA alone.¹ For those living with food allergies, everyday meals can feel like an incredibly daunting task. The risk of accidental exposure can cause significant stress, anxiety, and impact overall quality of life. From social gatherings to school lunches, careful planning is a constant part of life.

Did you know that just eight foods are responsible for roughly 90% of all food allergy reactions?² The top 8 food allergens are peanuts, tree nuts, milk, eggs, soy, wheat, fish, and shellfish, and recently, in the US, sesame was added to make that 9. These foods can cause a wide range of reactions, and knowing the symptoms, conditions they’re linked to, and safe alternatives is key to managing them effectively.

In this post, registered dietitian Andrea Hardy discusses types of food allergies, details about each of the allergens in the top 9, and how it relates to various allergic conditions.

In This Article:

• What are Food Allergies
• IgE and Non-IgE Mediated Allergies
• A Review of the Top 9 Food Allergies
  • Peanuts
  • Tree Nuts
  • Wheat
  • Dairy
  • Eggs
  • Soy
  • Fish
  • Shellfish
  • Sesame
• Spotlight on EoE

What are Food Allergies?

Food allergies occur when the immune system mistakenly identifies certain proteins in food as harmful substances that shouldn’t be there.

In response, the body triggers an allergic reaction, which can range from mild to severe. This is different from a food intolerance, which involves digestive discomfort, or a food sensitivity, that may involve the immune system but isn’t life threatening. 

IgE and Non-IgE Mediated Allergies

Allergies can be either IgE mediated or non-IgE mediated.

Non-IgE mediated allergies are on the rise,³ and include conditions like:

●      Eosinophilic esophagitis—a condition where the esophagus becomes inflamed due to an immune response to certain foods.

●      Eosinophilic esophagitis—a condition where the esophagus becomes inflamed due to an immune response to certain foods.

Understanding the difference between allergies, intolerances, and sensitivities is crucial, as it guides how these reactions are managed and treated safely.

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The Top 9 Food Allergens – An Overview

While any food has the potential to cause an allergic reaction, most serious reactions are triggered by just a handful of common foods. Below, we break down each of these common allergens, what to watch for, and tips for safe eating.

1. Peanuts

2. Tree Nuts

Long-term/related conditions: 

• May contribute to eczema or asthma exacerbations in sensitive individuals. 
• Some individuals may also experience oral allergy syndrome (OAS), where certain raw fruits, vegetables, or tree nuts trigger itching or tingling in the mouth due to a similarity to birch pollen proteins.⁷

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3. Wheat

Reactions/conditions:

Can cause immediate reactions in wheat allergy, non-celiac wheat sensitivity, or celiac disease. 

Long-term/related conditions: 

Wheat allergy is commonly linked to eosinophilic esophagitis, eczema flares, and asthma exacerbation in some cases.⁸

Fun facts: 

• Many people with wheat allergy can tolerate gluten-free grains like rice, corn and quinoa.
• Oats can be tolerated but should be certified gluten free due to cross-contact with wheat during production.
• While not safe for wheat allergies or celiac, individuals with non-celiac wheat sensitivity may be able to tolerate sourdough bread, as it’s partially broken down by the long fermentation process, which may make it easier to digest. 
• Wheat allergy is sometimes outgrown in childhood, though this isn’t always the case. And unlike celiac disease, which is lifelong, both wheat allergy and wheat sensitivity have the potential to change over time.

Safe eating & alternatives:

4. Dairy

Long-term/related conditions: 

• Dairy allergy is more common in infants and children and studies have found that about 80% this allergy by age 16.⁹
• In some cases, dairy allergy and eczema tend to cluster together.¹⁰

Fun facts: 

• Lactose-free products are not safe for dairy allergy (because they still contain milk protein), but they work well for lactose intolerance. 
• Some people with non-IgE mediated dairy allergy can tolerate extensively baked milk (like muffins or cookies), since heating alters the proteins—but always check with your allergist!

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5. Eggs

Fun facts: 

• Many egg-allergic children can tolerate baked egg in muffins or cakes, as heating changes egg protein structure. 
• One study even found that eating a tolerated amount of baked egg regularly appeared to speed up the transition to tolerating all forms of egg.¹²

safe eating & alternatives: 

• Use egg replacers in baking (like flax “eggs,” chia seeds, applesauce, or commercial replacers). 
• Plant-based mayonnaise and egg-free pastas are widely available.

6. Soy

Reactions/conditions:

Soy allergy can cause skin reactions, respiratory symptoms, or digestive upset. Soy intolerance (non-immune) can also mimic some of these symptoms.

Long-term/related conditions:

More common in children than adults, with many kids outgrowing it by school age. In adults, soy allergy may persist.¹³

7. Fish

Reactions/conditions: 

Fish allergy is typically IgE-mediated, with symptoms ranging from hives and vomiting to anaphylaxis.

Long-term/related conditions:

Fish allergy often persists for life. Because fish is an excellent source of omega-3 fatty acids, avoiding it can impact nutrient intake—making supplementation a helpful strategy.

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8. Shellfish

Reactions/conditions: 

Shellfish allergy is one of the most common food allergies in adults and often triggers severe reactions, including anaphylaxis.

9. Sesame

Fun Facts:

• Sesame was added as the 9^th major allergen in the US in 2023. With this change, manufacturers must list sesame clearly on ingredient labels, improving safety for those with a sesame allergy.
• Sesame has been a top priority allergen in Canada for a long time, meaning manufacturers must clearly list whether a food contains sesame.
• Sesame oil is sometimes used in cosmetics and hair care products. Those with a sesame allergy will need to label read for those ingredients.

Safe eating & alternatives:

• Watch for ‘may contains’ statements on baked goods—many facilities produce products with and without sesame, where cross contact can occur.
• Choose foods that are top-priority allergen free. The Grain Escape hamburger buns are a great alternative to sesame hamburger buns!

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Spotlight on Eosinophilic Esophagitis (EoE)

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated condition where white blood cells called eosinophils build up in the esophagus. This inflammation can cause symptoms like difficulty swallowing, food getting “stuck,” chest pain, and reflux that doesn’t always improve with medication.

EoE is often triggered by food proteins, and many of the top 9 allergens are the most common culprits—especially dairy, wheat, soy, and eggs. Unlike classic food allergies, which tend to cause immediate reactions, EoE symptoms are usually delayed and linked to long-term exposure.

How EoE differs from IgE-mediated food allergy

In classic IgE-mediated allergies, symptoms like hives, swelling, or anaphylaxis appear quickly after eating the food.

With EoE, the immune system reacts differently: the inflammation builds gradually in the esophagus and symptoms often appear hours or even days later. For this reason, allergy testing alone isn’t always reliable in diagnosing EoE, and food triggers are usually identified through elimination diets and follow-up endoscopies of the esophagus, with biopsies.

Why elimination diets are part of management

Because certain foods are strongly linked to EoE, allergen elimination diets are a cornerstone of treatment. The goal is to reduce esophageal inflammation, improve swallowing, and prevent long-term complications like strictures.

For some, this means removing one food group (such as dairy) and monitoring symptoms. Others may remove the top 9 allergens, or a group of them to determine how their EoE responds. 

This is why having access to allergy-friendly foods that are top 9 free can be so helpful for patients. The Grain Escape is top 9-free and provides patients with multiple allergies a nutritious option for bread products.

In Summary

Recognizing and respecting food allergies is essential—not only for those living with them but also for creating safe spaces for people with allergies in the community. 

While navigating allergies can feel overwhelming at times, the good news is that awareness, research, and food innovation are making it easier than ever to live well with dietary restrictions.

Safe alternatives are becoming more widely available, and food companies are stepping up to meet these needs. The Grain Escape products are one example of how allergen-friendly options can help people enjoy safe, satisfying meals without worry. 

With the right knowledge and support, managing food allergies is not about limitation, it’s about empowerment and finding foods that truly work for you.

If you’re living with food allergies or sensitivities, working with a registered dietitian can help you navigate safe food choices, prevent nutrient gaps, and feel confident in your eating patterns.

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About Andrea Hardy

Nutrition communicator and knowledge translator, Andrea Hardy is a registered dietitian from Calgary, Canada, where she runs Ignite Nutrition, a multi-disciplinary digestive health practice. She specializes in gut health and gastrointestinal diseases and is recognized in the media as Canada’s Gut Health Expert. Passionate about translating science into easy to digest information to support a healthy gut, Andrea Hardy has spoken on the TEDx stage, as well as internationally about digestive health. Follow her on Instagram at @andreahardyrd or tune into her gut health podcast Let’s Gut Real which is all about making nutrition science easy to digest!

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FootNotes

1. Food Allergy Research & Education. (n.d.). Facts and statistics. https://www.foodallergy.org/resources/facts-and-statistics ↩︎
2. Food Allergy Research & Education. (n.d.). Facts and statistics. https://www.foodallergy.org/resources/facts-and-statistics ↩︎
3. Labrosse, R., Graham, F., & Caubet, J. C. (2020). Non-IgE-Mediated Gastrointestinal Food Allergies in Children: An Update. Nutrients, 12(7), 2086. https://doi.org/10.3390/nu12072086 ↩︎
4. Dermatology Times. (2023). Eczema associated with heightened risk of peanut allergy in infants. https://www.dermatologytimes.com/view/eczema-associated-with-heightened-risk-of-peanut-allergy-in-infants ↩︎
5. Patel R, Koterba AP. Peanut Allergy. [Updated 2023 Jul 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538526/  ↩︎
6. Anaphylaxis UK. (n.d.). Peanut oil. https://www.anaphylaxis.org.uk/fact-sheet/peanut-oil/  ↩︎
7. American Academy of Allergy, Asthma & Immunology. (n.d.). Oral allergy syndrome (OAS). https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/oral-allergy-syndrome-(oas) ↩︎
8. Quirce, S., & Diaz-Perales, A. (2013). Diagnosis and management of grain-induced asthma. Allergy, Asthma & Immunology Research, 5(6), 348–356. https://doi.org/10.4168/aair.2013.5.6.348 ↩︎
9. American College of Allergy, Asthma & Immunology. (n.d.). Milk (dairy) allergy. https://acaai.org/allergies/allergic-conditions/food/milk-dairy/ ↩︎
10. National Eczema Association. (n.d.). Atopic dermatitis and allergies connection. https://nationaleczema.org/blog/atopic-dermatitis-and-allergies-connection/  ↩︎
11. American College of Allergy, Asthma & Immunology. (n.d.). Egg allergy. https://acaai.org/allergies/allergic-conditions/food/egg/ ↩︎
12. Food Allergy Research & Education. (n.d.). Egg allergy. https://www.foodallergyawareness.org/food-allergy-and-anaphylaxis/food-allergens/egg/ ↩︎
13. Food Allergy Canada. (n.d.). Soy allergy. https://foodallergycanada.ca/allergies/soy/ ↩︎
14. Anaphylaxis UK. (n.d.). Fish allergy. https://www.anaphylaxis.org.uk/fact-sheet/fish-allergy/ ↩︎
15. American College of Allergy, Asthma & Immunology. (n.d.). Shellfish allergy. https://acaai.org/allergies/allergic-conditions/food/shellfish/ ↩︎
16. Anaphylaxis UK. (n.d.). Fish allergy. https://www.anaphylaxis.org.uk/fact-sheet/fish-allergy/ ↩︎
17. Kaman, K., & Factor, J. M. (2022). A practical focus on sesame allergy and a brief review of other seed allergies. Journal of food allergy, 4(2), 151–157. https://doi.org/10.2500/jfa.2022.4.220008 ↩︎