The most common food allergies

Food allergies are a common health concern affecting millions of people worldwide. While it is possible for any food to cause an allergy, most food allergies are caused by  eight foods, known as the major food allergens. This article aims to provide useful information about some of the most common food allergies, how to manage them, and how to make an allergy diagnosis. 

Understanding Food Allergies

An allergy is an overreaction of the immune system to a substance that is harmless to most people. When a person is allergic to a certain food, the body’s immune system considers the proteins in that food to be dangerous invaders and mounts an attack. This response can lead to various symptoms, ranging from mild to severe (NHS, 2021). During an allergic reaction, IgE antibodies specific to the allergen cause a flood of chemicals to be released into the body, triggering the symptoms of allergies such as swelling, itching, trouble breathing, and hives.

It is estimated that the lifetime prevalence of food allergies in Europe is between 0.1 to 6.0% of the population (Nwaru et al., 2014). However, the prevalence varies greatly by geographic region and is influenced by factors such as genetics and environmental exposures. Food allergies are more common in children than adults, and many food allergies resolve themselves during childhood. It is estimated that six to eight percent of children and three percent of adults have a food allergy (Mayo Clinic, 2021).

The most common food allergies

The most common food allergens are peanuts, milk, eggs, fish, shellfish, wheat, soy, and tree nuts. These eight foods are responsible for about 90% of all food allergies (FDA, 2023). Read on to learn more about the eight most common food allergens.

Peanut Allergy

Peanut allergies are one of the most common food allergies, especially among children, and are often lifelong (FARE, 2021). Peanuts are not the same as tree nuts (e.g. almonds, cashews, or walnuts), as peanuts are actually in the legume family. Allergic reactions to peanuts can cause severe and potentially life-threatening anaphylaxis. Symptoms include skin rashes, swelling of the face and airway, and digestive problems. Avoiding peanuts and peanut products is crucial for managing this allergy, and people with peanut allergies should always carry an epinephrine injector (Epi-Pen) in case anaphylaxis occurs.

Dairy Allergy

A dairy allergy is an immune response to the proteins found in cow’s milk. It is one of the most common allergies in children, affecting about 2-3% of children under three years old (FARE, 2021). While up to 75% of children outgrow milk allergies, it is still one of the most common food allergies in adults. Symptoms can range from mild, such as hives and digestive problems, to severe, such as anaphylaxis.

It’s crucial to distinguish a dairy allergy from lactose intolerance, a condition where individuals lack the enzyme to digest lactose, a sugar in milk. While both can cause digestive symptoms after consuming milk, a dairy allergy can cause a severe life-threatening reaction, whereas lactose intolerance can’t. Furthermore, people with lactose intolerance may be able to consume lactose-free dairy products or use lactase tablets to consume dairy, whereas people with a dairy allergy should avoid the allergen altogether.

Egg Allergy

Egg allergy is another common allergy, especially in children, although many outgrow it by adolescence (ACAAI, 2021). Egg allergies can cause symptoms including skin rashes, shortness of breath, and stomach pain to severe anaphylaxis. People with an allergy to chicken eggs may also be allergic to other types of eggs, such as duck and quail. 

People with egg allergies are often advised to avoid them completely. However, this can be difficult as eggs are a hidden ingredient in many foods. It is important to be cautious of food products that might contain traces of eggs, like certain baked goods, salad dressings, or processed foods. Certain vaccines may also contain egg protein, including yellow fever, rabies, and flu vaccines (Bradley, 2022). If you have an egg allergy, speak to your doctor about which vaccines you can receive safely. 

Fish Allergy

Fish allergies are allergic reactions to finned fish such as cod, halibut, tuna, or salmon. This allergy is commonly seen in adults and can cause severe reactions (FARE, 2021). Symptoms usually appear within minutes or up to two hours after eating fish, and can include skin reactions, vomiting, digestive problems, respiratory issues, and anaphylaxis. It’s crucial for people with fish allergy to avoid all types of fish unless a doctor confirms that specific species can be safely consumed. 

Fish and shellfish are not closely related and having a fish allergy does not necessarily mean you need to avoid shellfish. However, it is important to avoid cross contamination between fish and shellfish. 

Shellfish Allergy

Shellfish allergies refer to an allergic reaction in response to either crustaceans (shrimp, lobster, and crab) or mollusks (scallops, oysters, clams, and mussels) (ACAAI, 2019). Crustaceans cause the largest number of allergic reactions, and some people with a shellfish allergy can eat mollusks without any reaction. However, this should be confirmed by an allergist before eating any type of shellfish, and be vigilant that cross-contamination between shellfish can occur.

Symptoms of a shellfish allergy can be mild (hives and vomiting) to severe symptoms (anaphylaxis). This allergy is generally lifelong, and the best approach is completely avoiding shellfish.

Wheat Allergy

A wheat allergy is an immune response to any of the proteins present in wheat. This allergy is common in children but may also develop in adults. The most common symptoms of a wheat allergy include skin rash, nausea, headache, difficulty breathing, and, in rare cases, anaphylaxis. Most children with wheat allergies outgrow them by adulthood- approximately 65% of children with wheat allergies have outgrown them by age 12 (ACAAI, 2021). 

It is important to note that wheat allergy is different from celiac disease, which is an autoimmune disorder triggered by gluten, and non-celiac gluten sensitivity, which involves digestive problems in response to gluten ingestion but doesn’t involve an immune response. Management of wheat allergies involves avoiding the allergen completely. This requires learning which foods contain wheat or were produced in a  facility where cross-contamination with wheat could have occurred. While many foods contain wheat (including breads, crackers, pastas, and other products with wheat added), it is possible to substitute wheat products for other grains such as rice, quinoa, and oats.

Soy Allergy

Soy allergies are a common food allergy in children and are usually outgrown by adulthood (ACAAI, 2019). Symptoms of a soy allergy include irritation of the skin and mucous membranes, vomiting, diarrhea, wheezing, and anaphylaxis in rare cases. Soy is common in many foods, including processed foods, Asian cuisine, and infant formulas, making label-reading an essential habit for individuals with this allergy. People with soy allergies can often eat soy derivatives, including highly refined soybean oil and soy lecithin. Speak to your allergist about whether it is safe to consume these products (ACAAI, 2019). 

Tree Nut Allergy

Tree nut allergies are allergies to any type of tree nut, including walnuts, almonds, hazelnuts, pecans, cashews, and pistachios. This allergy is different from a peanut allergy, which is considered a legume related to beans and soy. Tree nut allergies are common in both children and adults and are usually lifelong (FARE, 2022). Additionally, around 50% of people that are allergic to one tree nut will have allergies to other tree nuts. 

People with tree nut allergies are at risk of life-threatening anaphylaxis. It’s important to avoid all types of tree nuts and their products and to carry an epinephrine injector if you have a tree nut allergy. 

Allergy Testing

Understanding what triggers your symptoms is a crucial step in managing a food allergy. There are several types of allergy tests available, including skin prick tests, blood tests, and elimination diets.

Skin prick tests involve placing a small amount of the suspected allergen on the skin and then pricking the area with a tiny lancet. If a wheal (small red bump) develops, it indicates a possible allergy. This test must be done under the supervision of a doctor, as there is a possibility that a severe allergic reaction may occur. Skin prick tests are considered to be a reliable indicator of allergies, but may not be possible in certain groups due to the skin irritation they cause.

Blood tests, also known as IgE tests, measure the level of specific IgE antibodies in the blood in response to individual allergens. This test can be performed either in a doctor’s office or from home. The advantage of this test is that there is no risk of allergic reaction. However, confirmatory follow-up testing may be required to definitively diagnose an allergy. 

An elimination diet involves removing suspected foods from the diet for a period and then reintroducing them one by one to identify which causes symptoms. Elimination diets may be recommended by your doctor if your allergy is not known to cause severe symptoms like anaphylaxis. 

Another form of allergy testing is the oral food challenge, considered the most accurate method to diagnose food allergies. Under close medical supervision, patients consume the suspect food in gradually increasing amounts to see if an allergic reaction occurs (AAAI, 2020). 

Would you like to check your body’s reactivity to more than 295 allergens, including all common food allergens? Homed-IQ’s Allergy Test Extensive is an IgE blood test that can be taken from home. After collecting your blood sample, simply mail it to our certified laboratory for analysis. The comprehensive laboratory report contains information on your body’s reactivity to each individual allergen that can be brought to your doctor for follow-up testing and care.

Living with Food Allergies 

Living with food allergies can be challenging, but with the right tools and strategies, individuals can have a fulfilling and healthy lifestyle. Avoidance of the allergen is the primary method of managing food allergies (Mayo Clinic, 2021). This involves carefully reading food labels and asking questions about food preparation when eating out. It’s also important to educate family, friends, and school or work personnel about your allergies so they can help prevent exposure. 

In many countries, it is required by law to clearly label common food allergens on the ingredients list of a food. It is also required to report if the food was produced in a facility where cross contamination may have occurred. New legislation regarding the labeling of allergens in food products is vital in preventing accidental consumption of allergens and a potentially deadly allergic reaction.

Carrying an epinephrine auto injector (EpiPen) is crucial for those with severe allergies to treat potential anaphylaxis (Mayo Clinic, 2021). For those with less severe symptoms, reactions may be managed with antihistamines. Regular check-ups with a healthcare provider are also recommended to monitor food allergies, especially in children who may outgrow the allergy over time. While living with food allergies requires vigilance, with the right approach they can be effectively managed allowing for a healthy, fulfilling life.

References

American College of Allergy, Asthma and Immunology. (2023). Egg Allergy | Causes, Symptoms & Treatment. ACAAI. https://acaai.org/allergies/allergic-conditions/food/egg/

American College of Allergy, Asthma and Immunology. (2022). Wheat & Gluten Allergy | Symptoms & Treatment. ACAAI. https://acaai.org/allergies/types/food-allergies/types-food-allergy/wheat-gluten-allergy

American College of Allergy, Asthma and Immunology. (2022c, July 28). Soy Allergy | Causes, Symptoms & Treatment. ACAAI. https://acaai.org/allergies/allergic-conditions/food/soy/

Bradley, J. (2022). What Vaccines Are Safe for People Allergic to Eggs? Verywell Health. https://www.verywellhealth.com/can-you-get-vaccines-if-you-are-allergic-to-eggs-1324082

FDA. (2023). Food Allergies. U.S. Food And Drug Administration. https://www.fda.gov/food/food-labeling-nutrition/food-allergies#:~:text=This%20law%20identified%20eight%20foods,peanuts%2C%20wheat%2C%20and%20soybeans.

Food Allergy Research & Education. (2018). Fish. FoodAllergy.org. https://www.foodallergy.org/living-food-allergies/food-allergy-essentials/common-allergens/fish

Food Allergy Research & Education. (2022). Peanut. FoodAllergy.org. https://www.foodallergy.org/living-food-allergies/food-allergy-essentials/common-allergens/peanut

Food Allergy Research & Education. (2021). Tree Nut. FoodAllergy.org. https://www.foodallergy.org/living-food-allergies/food-allergy-essentials/common-allergens/tree-nut

Food Allergy Research and Education. (2023). Milk. FoodAllergy.org. https://www.foodallergy.org/living-food-allergies/food-allergy-essentials/common-allergens/milk

Mayo Clinic. (2021, December 31). Food allergy – Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/food-allergy/symptoms-causes/syc-20355095

NHS. (2023, January 12). Food allergy. nhs.uk. https://www.nhs.uk/conditions/food-allergy/

Nwaru, B. I., Hickstein, L., Panesar, S. S., Roberts, G., Muraro, A., & Sheikh, A. (2014). Prevalence of common food allergies in Europe: a systematic review and meta-analysis. Allergy, 69(8), 992–1007. https://doi.org/10.1111/all.12423

Shellfish Allergy | Causes, Symptoms & Treatment | ACAAI Public Website. (2022, April 13). ACAAI Public Website. https://acaai.org/allergies/allergic-conditions/food/shellfish/

Tree Nut. (2023). FoodAllergy.org. https://www.foodallergy.org/living-food-allergies/food-allergy-essentials/common-allergens/tree-nut