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Knowledge Base » Food Hygiene » Understanding the Common Culprits: Top Allergenic Foods

Understanding the Common Culprits: Top Allergenic Foods

Last updated on 25th April 2024

It is estimated that more than two million people in the UK have a diagnosed food allergy. A food allergy is an abnormal immune response triggered by consuming a particular food or ingredient. When someone with a food allergy ingests or comes into contact with the allergen, their immune system mistakenly identifies certain proteins in the food as harmful invaders and releases chemicals, such as histamine, to defend the body.

This can result in a range of adverse symptoms, which can range from mild to severe and life-threatening. Symptoms of a food allergy can include:

  • Skin reactions, e.g. hives, itching and a rash.
  • Gastrointestinal symptoms, e.g. nausea, vomiting, diarrhoea and abdominal pain.
  • Respiratory symptoms, e.g. sneezing, runny nose, nasal congestion, coughing, wheezing and shortness of breath.
  • Cardiovascular symptoms, e.g. rapid or weak pulse, light-headedness and fainting.
  • Swelling of the lips, tongue, throat or face.
  • Anaphylaxis – a severe and potentially life-threatening allergic reaction characterised by a sudden drop in blood pressure, difficulty breathing, loss of consciousness and other serious symptoms. In some cases, anaphylaxis can result in death.

Food allergies can develop at any age, but they often appear during childhood and may persist into adulthood. 

An allergenic food is a type of food or ingredient that has the potential to trigger an allergic reaction in certain individuals. While there are more common allergenic foods (that more people are allergic to), any food has the potential to cause an allergic reaction in susceptive individuals. It is essential for individuals with food allergies to carefully manage their diet, read food labels and take precautions to avoid exposure to allergenic foods to prevent allergic reactions.

The Allergenic Foods List

The Allergenic Foods List

According to the NHS, the most common food allergies are:

Cows’ milk

This is the most common food allergy in babies and young children. The proteins that are present in cows’ milk can trigger a mild to severe allergic reaction. Someone with a milk allergy will likely be allergic to a range of dairy products that contain milk, including cheese, yoghurt, butter and chocolate. A breastfed infant with a milk allergy can experience an allergic reaction if their mother consumes milk, as the proteins from the milk can pass into the breast milk. 2%-3% of babies under 12 months of age are allergic to cows’ milk in the UK, although many of them grow out of their allergy. If an older child or adult has a milk allergy, it is more likely to be a serious, lifelong allergy.


Egg allergies are also very common in childhood, with many children later outgrowing their allergy. The majority of people with an egg allergy are allergic to a protein in the egg white. However, the yolk should also be avoided as it can be contaminated by the white. Someone who is allergic to eggs must also avoid any products that contain eggs, even if it is only a small amount. For example, mayonnaise, cakes, pastries and other baked goods, marshmallows, desserts and puddings with a glaze, and some pasta.


Peanut allergies are another common allergy. Although some people with peanut allergies only experience a mild to moderate allergic reaction (e.g. hives, itching, abdominal pain and swelling of the lips, face and eyes), peanut allergies can also be extremely dangerous. Peanuts are one of the most commonly implicated foods in cases of anaphylaxis, a life-threatening allergic reaction that can result in death. Peanuts are different to other types of nuts as they grow underground (rather than on trees) and are from a different family of plants. Many people with a peanut allergy are not allergic to other types of nuts.


The soybean is a type of legume (similar to beans, peas and lentils) and is another common food allergy. Soybeans, although not often eaten alone, are used in many different foods and ingredients, including soy milk, soy flour, soy sauce, tofu and other textured vegetable protein (TVP) and soy nuts.

Peas and chickpeas

Similarly to peanuts and soybeans, peas and chickpeas are types of legumes. Some people experience cross-reactivity between lentils, peas, chickpeas and peanuts, whereas other people have an allergy to one legume and can safely eat other types of legumes without experiencing an allergic reaction.

Tree nuts

Tree nuts include almonds, hazelnuts, pecans, cashews, pistachios and Brazil nuts. Tree nut allergies are another common food allergy that can result in a severe allergic reaction or anaphylaxis. It is possible to be allergic to only one type of tree nut, as different nuts have different proteins. However, some people are allergic to all tree nuts.


There are two different types of shellfish: 

– Crustacea: Prawns, crab and lobster.

– Molluscs: Clams, mussels, oysters and scallops.

Alongside peanuts and tree nuts, shellfish is the other type of allergen that is most frequently linked with anaphylaxis. Unlike other food allergies, an allergy to shellfish is usually lifelong. Most shellfish allergies are related to crustaceans.


Wheat allergies are common in infancy and childhood, with 45% of children outgrowing a wheat allergy by the age of five. Wheat is found in a lot of foods, meaning this can be a more difficult allergy to navigate. Some common foods containing wheat include bread, breakfast cereals, pasta, pizza, couscous, cakes and other desserts, soups, sauces, gravy and many ready meals.

Allergenic Food Characteristics

Allergenic Food Characteristics

There are specific characteristics of food allergens that classify a particular food as an allergenic food.

  • Protein content
    Allergenic foods contain proteins that have the potential to trigger allergic reactions in susceptible individuals. These proteins are recognised by the immune system as foreign invaders which can lead to an abnormal immune response.
  • Allergen presence
    The presence of specific allergens sets apart these foods. For example, milk contains allergenic proteins like casein and whey, while peanuts contain allergenic proteins such as Ara h1, Ara h2 and Ara h3.
  • Resistant to heat treatments
    Allergenic proteins can vary in their stability and susceptibility to heat. Although some proteins are more susceptible to heat than others (meaning the protein may break down during cooking, reducing their allergenicity), many proteins remain intact, even after exposure to high temperatures. For some allergens, cooking or processing can actually increase the allergenicity of certain proteins by exposing hidden epitopes (the specific sites on the protein molecule that trigger an immune response) that were previously masked. Ultimately, the effect of heat on allergenic proteins can vary depending on factors such as the specific protein, the degree of heat applied and individual differences in sensitivity. It is safe to assume that processing the food, for example, boiling it, cooking it or adding ingredients or chemicals, does not break down the allergenic protein.
  • Versatile forms
    Allergenic foods can be found in various forms, including whole, processed or hidden within other ingredients. For example, milk can be consumed as a liquid or as processed products such as cheese, chocolate or yoghurt. Similarly, peanuts can be eaten whole, in the form of peanut butter, or as an ingredient in sauces or baked goods.
  • Potential hidden allergens
    An important characteristic of allergenic foods is their potential to be hidden within other foods or ingredients. This makes it challenging for individuals with allergies to identify and avoid them. For example, milk derivatives like whey or casein can be hidden in processed foods, while egg albumin may be present in certain sauces or baked goods without being explicitly listed.

Allergen Profiles

Understanding where these allergens are commonly found is essential for individuals with food allergies to effectively avoid them and prevent allergic reactions. Although people are usually aware of how dangerous consuming an allergen is and may avoid eating or drinking the allergen in its original form, many people forget about allergens in other forms or when the allergen is a small ingredient in a larger dish.

  • Milk
    Common sources: Milk is found in various dairy products such as milk, cheese, yoghurt, butter, ice cream and cream-based sauces. Milk is also commonly used in baked goods, desserts and some processed foods.
  • Eggs
    Common sources: Eggs are commonly found in baked goods (such as cakes, cookies and muffins), breakfast foods (such as omelettes, waffles and pancakes), mayonnaise, salad dressings, pasta and some processed foods like breaded meats or battered fish.
  • Peanuts
    Common sources: Peanuts are present in various foods such as peanut butter, snack bars, cookies, candies, Asian dishes (like satay sauce) and certain sauces. They are also used as a common ingredient in many packaged foods, including processed snacks and baked goods.
  • Tree nuts, e.g. almonds, hazelnuts, pecans, cashews, pistachios and Brazil nuts
    Common sources: Tree nuts are found in many foods including nut butter and nut milk (such as almond milk or cashew butter), baked goods (such as cakes, cookies and granola bars), cereals, salads and desserts. They are also commonly used in some cuisines; for example, peanut oil is often used in Chinese and Indian cuisine and as toppings or garnishes in various dishes.
  • Soy
    Common sources: Soy can be found in soy milk, tofu, soy sauce, miso, tempeh, edamame and many processed foods such as baked goods, soups, sauces and meat substitutes. It is also used as a common ingredient in many packaged foods, including snacks and processed meats.
  • Wheat
    Common sources: Wheat is a staple ingredient in bread, pasta, cereals, baked goods (such as bread, cakes and cookies), flour tortillas, couscous and many processed foods like sauces, soups and processed meats. It is also commonly used as a thickening agent in soups, sauces and gravies.
  • Fish
    Common sources: Fish allergens are present in various types of fish such as salmon, tuna, cod and haddock and in foods like sushi, fish sauce, fish fingers and tinned fish products (e.g. tinned tuna). They are also used as ingredients in many packaged foods, including soups, sauces and prepared meals.
  • Shellfish
    Common sources: Shellfish allergens can be found in crustaceans like prawns, crab and lobster, as well as molluscs such as clams, mussels and oysters. They are commonly found in dishes like seafood pasta, sushi, paella, seafood soups and stir-fries. Shellfish is also used as an ingredient in many packaged foods, including soups, sauces and frozen meals.
Hidden Allergens

Hidden Allergens

Allergenic ingredients can be disguised under alternative names or terms in ingredient lists, further complicating the identification process for consumers. This practice is often employed by food manufacturers to enhance flavour and texture or extend shelf life without explicitly indicating the presence of common allergens. In the UK, any hidden allergens must still be clearly labelled with the allergen in brackets; for example, you may see an ingredient list state: whey powder (MILK). However, this is not true in all countries, so being aware of hidden allergens and their alternative names is recommended, particularly for people who travel outside of the UK.

Some examples of alternative names for common allergens include:

  • Milk
    Alternative names: casein, whey, lactoglobulin, lactalbumin, lactose, butterfat, ghee, curds and certain artificial flavourings.
  • Egg
    Alternative names: albumin, globulin, lysozyme, ovomucin, ovomucoid, Ovo vitellin and lecithin (unless specifically stated as soy lecithin).
  • Peanut
    Alternative names: groundnut, arachis oil, beer nuts, monkey nuts and certain natural and artificial flavourings (e.g. nutty flavour).
  • Tree nuts
    Alternative names: almond extract, walnut oil, marzipan, praline, nougat, gianduja and certain natural and artificial flavourings (e.g. nutty flavour).
  • Soy
    Alternative names: edamame, soybean oil, soy protein, soy lecithin, textured vegetable protein (TVP) and certain emulsifiers and stabilisers.
  • Wheat
    Alternative names: semolina, durum, farina, bulgur, spelt, Kamut, couscous and certain food additives and thickeners (e.g. modified food starch).
  • Fish
    Alternative names: anchovy, sardine, surimi, caviar, fish gelatine and certain natural and artificial flavourings (e.g. fishy flavour).
  • Shellfish
    Alternative names: crustaceans, molluscs, chitin, glucosamine and certain natural and artificial flavourings (e.g. seafood flavour).
  • Peas and chickpeas
    Alternative names: alternative names for peas may include terms such as legumes, pulses or specific varieties like green peas or split peas.

Navigating hidden allergens requires vigilance and awareness on the part of consumers, especially those with food allergies. Reading food labels carefully, knowing alternative names for common allergens and asking about ingredients when dining out are essential strategies for avoiding hidden allergens and preventing allergic reactions. Additionally, advocating for clearer labelling regulations and increased awareness of hidden allergens in food products can help improve food safety for individuals with food allergies.

Cross-Contact Risks

Cross-contact in food preparation refers to the transfer of allergenic proteins from one food to another, potentially leading to the unintentional presence of allergens in foods that are supposed to be allergen-free. This can occur through contact with shared surfaces, utensils, equipment or hands that have come into contact with allergenic foods.

If you are eating at a restaurant, café or another food establishment, it may be necessary to ask about their kitchen practices to check whether there is a risk of cross-contact. For example, you can ask whether the kitchen has separate food preparation areas, designated areas for preparing allergen-free food and separate utensils and equipment to reduce the risk of cross-contact.

You could also ask about the restaurant’s protocols for preventing cross-contact, including staff training on allergen awareness, the establishment’s cleaning procedures and the methods they use to avoid cross-contact during food preparation.

To ensure no allergens are present, particularly allergens that are listed under other names, request access to ingredient lists or allergen information for menu items to verify their suitability for your dietary needs. Remember, there are several laws in the UK that protect people with food allergies, including:

  • The Food Information (Amendment) Regulations 2019: These regulations set out the responsibilities of food businesses, including restaurants, to provide information regarding allergens.
  • The Food Safety Act 1990: Under this legislation, food businesses in the UK have a legal obligation to ensure that the food they serve is safe and suitable for consumption. This includes taking appropriate measures to prevent cross-contamination and cross-contact and provide accurate allergen information to consumers.
  • Food Information Regulations 2014: These regulations implement the EU FIC in the UK and require food businesses to provide allergen information for non-prepacked foods, including those sold in restaurants, takeaways and catering establishments. The regulations specify the allergens that must be declared.

Ensure that staff members are knowledgeable about the ingredients used in each dish and communicate your food allergies clearly. People without a food allergy often do not understand the severity of the risk so emphasising the importance of avoiding cross-contact and providing specific details about your allergy and the risks can help to ensure your safety. 

Some people with food allergies also prefer to eat out during off-peak times, when the restaurant may be less busy and staff are less likely to make contamination errors. 

Many people find it much easier to manage their food allergy at home, as they are able to limit which food items are in their kitchen and what equipment, utensils and food preparation areas they use (if they are also preparing allergen-containing foods). However, there are still some additional steps you can follow to reduce the risk of cross-contact at home, including:

  • Designate allergen-free areas
    Create separate preparation areas in your kitchen for allergen-free cooking to minimise the risk of cross-contact. Use separate cutting boards, utensils and cooking equipment for preparing allergen-free meals.
  • Clean and sanitise thoroughly
    Regularly clean and sanitise kitchen surfaces, countertops, utensils and equipment to prevent cross-contact. Use hot, soapy water or designated allergen-safe cleaning products to ensure thorough sanitation.
  • Read labels carefully
    Check food labels for allergen information and avoid products that may contain allergens or have been processed on shared equipment with allergenic foods.
  • Cook separately
    Cook allergen-free meals separately from dishes containing allergens to avoid cross-contact. Use separate pots, pans and cooking utensils and consider using colour-coded equipment to distinguish between allergen-free and allergenic items.
  • Communicate with family members
    Educate family members or housemates about the importance of preventing cross-contact and encourage them to follow safe food handling practices to protect individuals with food allergies.
Reading Labels and Allergen Statements

Reading Labels and Allergen Statements

There are 14 regulated food allergens in the UK. If any of these 14 allergens are used in food, food businesses must inform you of the presence of this allergen. For packaged food, this means the allergen must be specifically stated on the packaging and highlighted (e.g. underlined or in bold). The 14 allergens are:

  • Celery
  • Cereals
  • Crustaceans
  • Eggs
  • Fish
  • Lupin
  • Milk (cows)
  • Molluscs
  • Mustard
  • Nuts
  • Peanuts
  • Sesame seeds
  • Soya
  • Sulphur dioxide

If the food contains other allergens, these must be clearly listed on the label, although they do not need to be highlighted. 

Under Natasha’s Law, all food retailers must display the full ingredient list and allergen labelling must be present on any food item that is pre-packed for sale. If any of the 14 major allergens are present, they must be emphasised on the packaging. 

Allergen statements and precautionary labelling play an integral role in protecting individuals with food allergies from accidental exposure to allergens. They provide vital information about potential allergen presence, allowing consumers to make informed choices about the foods they consume.

When reading labels and allergen statements, there are some ways that people with allergens can help to protect themselves, including:

  • Check the ingredients list
    Look for allergenic ingredients such as milk, eggs, peanuts, tree nuts, soy, wheat and shellfish listed in the ingredients. These ingredients should be highlighted, underlined or printed in bold for easier identification.
  • Check for allergen statements
    Look for allergen statements or declarations, which indicate if the product contains common allergens. Statements like ‘Contains: [allergen]’ or ‘May contain traces of [allergen]’ alert consumers to potential allergen presence.
  • Be aware of hidden allergens
    As mentioned earlier, some allergens can be listed under other names (although this is not legal in the UK). If you are travelling abroad or ordering food products from another country, ensure you check for hidden allergens. People with allergies need to be aware that allergens may be present in unexpected places or under different names. Be vigilant for alternative names of allergenic ingredients and familiarise yourself with common hidden sources of allergens.
  • Consider cross-contact risks
    Be cautious of products that may have come into contact with allergens during manufacturing or processing. Precautionary labels such as ‘Produced in a factory that also processes [allergen]’ or ‘Manufactured on shared equipment with [allergen]’ indicate potential cross-contact risks.
  • Ask questions
    If you are uncertain about a product’s ingredients or allergen status, don’t hesitate to ask staff for clarification or contact the manufacturer directly for more information.
  • Stay informed
    Stay updated on allergen labelling regulations, common hidden sources of allergens and emerging food products or ingredients that may pose risks to individuals with allergies.

Managing Allergenic Foods in Your Diet

Managing allergenic foods in your diet can feel overwhelming. Managing food allergies requires you to be diligent every day. With the right strategies and support, people with allergies can protect their health while still living the lifestyle they want with minimal risks of an allergic reaction. 

Some ways you can help to manage food allergens include:

  • Know your allergens
    First and foremost, identify your specific food allergens by undergoing allergy testing or consulting with a healthcare professional. Understanding your allergies is crucial for effectively managing your diet.
  • Read food labels
    Develop the habit of carefully reading food labels to identify allergenic ingredients and potential cross-contact risks. Look for alternative names for common allergens and be wary of hidden sources.
  • Communicate your allergies
    Inform restaurant staff, friends, family and caregivers about your food allergies to ensure they understand the seriousness of your condition. Clearly communicate your dietary restrictions to avoid accidental exposure to allergens.
  • Plan ahead
    When dining out or attending social gatherings, plan ahead by researching restaurant menus or informing hosts of your allergies in advance. Consider bringing safe snacks or meals with you to ensure you have options available.
  • Cook at home
    Prepare meals at home whenever possible to have better control over ingredients and cooking methods. Experiment with allergy-friendly recipes and substitute allergenic ingredients with safe alternatives.
  • Explore allergy-friendly foods
    Discover allergy-friendly alternatives to common allergenic foods. There are now numerous allergy-friendly products available, such as dairy-free milk alternatives, wheat-free bread and nut-free spreads.
  • Seek professional guidance
    Consult with allergists, immunologists or registered dietitians for personalised guidance and support in managing your food allergies. They can provide comprehensive dietary advice, help you navigate food challenges and develop meal plans tailored to your needs.
  • Educate yourself
    Stay informed about food allergies, emerging research and advancements in allergy management. Attend support groups, read reputable sources and engage with online communities to share experiences and learn from others with similar dietary restrictions.
  • Stay prepared
    Carry emergency medication, such as epinephrine auto-injectors, if prescribed by your healthcare provider. Learn how to recognise the signs of an allergic reaction and how to administer emergency treatment if needed.
  • Stay positive
    Living with food allergies can be challenging, but it’s essential to maintain a positive outlook and focus on the many safe and delicious foods that you can enjoy. With proper planning, education and support, managing your allergenic foods in your diet can become second nature.
Raising Awareness

Raising Awareness

Allergenic foods can have serious consequences for individuals with food allergies, including life-threatening allergic reactions and reduced quality of life. Raising awareness about allergenic foods is essential for public health and safety. Increased awareness helps individuals recognise the signs and symptoms of food allergies, understand the importance of allergen avoidance and learn how to respond effectively in emergency situations.

By promoting understanding and empathy, awareness initiatives help reduce the stigma associated with food allergies. Raising awareness can help create a supportive environment where individuals with food allergies feel comfortable disclosing their dietary needs and seeking assistance when necessary. Raising awareness can also lead to advocacy efforts aimed at improving food labelling laws, increasing access to allergy-friendly foods and implementing allergen-safe practices in restaurants and food establishments. This was the case with Natasha Ednan-Laperouse, who tragically died aged 15 after eating a sandwich containing sesame seeds that was not labelled as containing the allergen. Her family have since successfully campaigned for law changes (Natasha’s Law) to protect other people with food allergens and have significantly raised awareness of food allergens. 

Although we have come a long way in the UK with the knowledge and understanding surrounding food allergens and the laws and regulations that are put in place to protect people with food allergens, there is still a significant way to go. 

If you would like to help raise awareness of food allergies, below is a list of some things you can do:

  • Spread the word
    Sharing information about allergenic foods with friends, family members, colleagues and social networks can help to raise awareness of food allergies. Simple conversations and social media posts can help raise awareness and reach a wider audience.
  • Educate others
    Educate people around you about the importance of allergen awareness, including how to read food labels, recognise allergic reactions and provide support to individuals with food allergies.
  • Lead by example
    Be a role model for allergen awareness by practising safe food handling practices, accommodating dietary needs at social gatherings and advocating for inclusive policies in schools, workplaces and communities.
  • Support those with food allergies
    Encourage others to offer understanding and support to individuals with food allergies. This can include being mindful of allergens when preparing or sharing food, respecting dietary restrictions and learning how to administer emergency treatment if needed.
  • Participate in awareness campaigns
    Encourage others to participate in allergen awareness campaigns, fundraising events and community initiatives aimed at supporting individuals with food allergies and promoting safer food environments.

By working together to raise awareness about allergenic foods, we can create a more inclusive and supportive society where individuals with food allergies can eat safely and enjoy a higher quality of life.

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About the author

Nicole Murphy

Nicole Murphy

Nicole graduated with a First-Class Honours degree in Psychology in 2013. She works as a writer and editor and tries to combine all her passions - writing, education, and psychology. Outside of work, Nicole loves to travel, go to the beach, and drink a lot of coffee! She is currently training to climb Machu Picchu in Peru.

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