The Best and Worst Foods for Allergies

While many of us experience seasonal allergies, some are triggered by certain foods. Peanuts and shellfish are among the most common triggers for food allergies, but not consuming them may not be enough to avoid a potentially serious allergic reaction. Should we avoid foods we're allergic to? Are there substitutes that we can eat? Which foods are allergy busters?

Food Allergy Symptoms

Food allergies are not to be taken lightly because an allergic reaction can lead to an emergency room visit. In the United States, 32 million people have a life-threatening food allergy. They are very common in children, affecting one in 13 children.

A food allergy occurs when your immune system generates a response to a specific food. Family history of a food allergy, asthma, and a history of other allergies like hay fever can put you at higher risk of food allergies.

Food allergy symptoms vary in severity and some may overlap with those of other medical conditions. They can include:

• Hives or rash
• Itchy mouth and throat
• Swollen tongue, lips, and eyelids
• Hoarse voice
• Difficulty swallowing
• Coughing or wheezing
• Shortness of breath
• Abdominal pain
• Diarrhea and vomiting
• Lightheadedness or dizziness
• Loss of consciousness

A severe and potentially life-threatening allergic reaction is anaphylaxis. It can occur within seconds or minutes of exposure to an allergen.

Common Food Allergies: The Big Eight

There are several major foods that can cause allergies. In the United States, allergies to these foods make up 90% of all food allergies. Labels for processed foods must list these ingredients in compliance with the U.S. Food Allergen Labeling and Consumer Protection Act (FALCPA). These include:

• Milk: Allergy to milk is the most common allergy among children. Many, but not all, outgrow the allergy. You can be allergic to sheep’s, cow's, and goat’s milk. People with milk allergies should be aware that there may be milk proteins in processed food. 
• Eggs: Eggs are a primary food source and ingredient in food products around the world. Egg allergy is an Immunoglobulin E (IgE)-mediated food allergy. IgE is an antibody that is produced by the immune system in response to a threat. Proteins in both egg white and egg yolk can induce an allergic response.
• Fish: Parvalbumin, a protein found in fish, may trigger food allergies. Cooking doesn’t destroy the protein. The severity of this type of allergy depends on the amount consumed and individual sensitivity.
• Shellfish: These include shrimps, prawns, crabs, and lobsters. The allergen tropomyosin causes shellfish allergies. Shellfish retains this allergen even when it's cooked.
• Tree nuts: They include Brazil nuts, chestnuts, hazelnuts, pine nuts, almonds, pecans, coconuts, cashews, peanuts, and walnuts. The allergens responsible for nut allergy can include the seed storage proteins vicilins, legumins, and albumins, plant defense-related proteins, and profilins, a type of plant protein. People with nut allergies often react to several different nuts, suggesting that cross-reactivity between nut allergens is common.
• Wheat and grains: Allergies to wheat and grains are more frequently seen among infants, which often clear up after a few years. Allergy symptoms can range from mild skin or gut reactions to anaphylaxis. Note that wheat allergies and celiac disease are different. Wheat allergies are the immune system’s reaction to a protein within wheat, while celiac disease is an immune reaction to gluten. If you have a wheat allergy, you can still consume gluten from other non-wheat sources. 
• Soybean: Soybeans are a type of legume. However, allergies to soy are caused by the allergens vicilin and legumin. Both are resistant to heat. Soybeans are widely used in food products as emulsifiers and texturizers.

What to Eat or Skip

You need to look at processed food labels carefully to ensure the product does not include any of the ingredients that cause your allergies. 

For egg allergies, avoid products that contain albumin, ovalbumin, ovomucin, and ovomucoid. You should also avoid condiments like mayonnaise, beverages like eggnog, egg substitutes, fat substitutes made with egg, and common pantry staples like pasta and packaged cake or pancake mix. There are many food items you can eat that don’t list eggs as an ingredient, including several breads, crackers, and cereals, certain soups, and egg-free breaded meats.

If you have dairy allergies, keep an eye out for artificial butter flavor, butter and butterfat, buttermilk, casein (found in cheese), hydrolysates, lactalbumin, and lactalbumin phosphate, lactose, lactoglobulin, lactoferrin, whey, and yogurt. You’ll be surprised to find dairy in foods like hot dogs and sausages. You can consume various nut milks, oat milk, milk-free breads, eggs prepared without milk, meats not prepared in milk, pasta, potatoes (without cheese or prepared with butter or cream), and non-dairy soups.

Apart from avoiding peanuts and tree nuts, make sure to also avoid artificial nut products, oils derived from nuts, chocolates with nuts, nougat, nut extracts, nut milks, nut pastes, and nut flours. 

If you have a wheat allergy, remember that many foods like soups contain wheat. You should avoid a variety of flours along with foods made from wheat-like pasta, matzoh, cracker meal, bread crumbs, and farina. You can substitute wheat-based breads and cereals with rye, rice, corn, barley, potato, and oatmeal products. You may be able to consume some desserts that don’t contain wheat like tapioca, custards (not thickened with flour), certain cookie brands, and rice pudding. 

Anyone with a soy allergy must avoid a long list of soy products from edamame to tofu. Make sure that soups, Asian food, certain vitamins like vitamin E, vegetable gum, and starch contain no soy.

Diagnosis and Treatment for Food Allergies

A few tests can be used to diagnose food allergies.

Skin Prick Test

Food allergies can be diagnosed with a skin prick test (SPT). Your immunologist will place a drop of extract containing a small amount of the suspected allergen on your forearm and scratch the skin so that the extract is absorbed.

By itself, the positive result indicates that your body has made allergic antibodies to a specific food. However, it's not enough for a diagnosis. Your doctor will use findings from your medical history and physical exam to interpret your results.

Radioallergosorbent Test

Your doctor may also diagnose food allergies with a radioallergosorbent test (RAST), which is a blood test that measures the amount of the allergic antibody IgE produced when your blood is exposed to a specific food protein. RAST is often used in cases of patients who cannot tolerate SPT.

A specific type of RAST called ImmunoCAP has been studied more than others for its use in food allergy. ImmunoCAP allows your doctor to compare your test results with known values and ranges that show the relative likelihood of a food allergy.

Your doctor will take a blood sample and send it to a lab to be tested. Like the skin prick test, RAST can detect the presence of IgE, but a positive result does not in itself make a food allergy diagnosis.

Oral Food Challenge

Oral food challenge (OFC) is the most accurate test to determine whether you have a food allergy. It can also determine if you have outgrown one.

During an OFC, you will eat pre-measured doses of a suspected food allergen and be closely monitored for any symptoms. If there are any signs of a reaction, your doctor will stop the test and administer medications as needed. The goal is for you to tolerate a full serving of a certain food by the end of the test.

Atopy Patch Testing

Atopy patch testing (APT) is used in people who have had documented reactions to a certain food, especially those with atopic dermatitis (itchy inflammation of the skin), but whose skin prick and blood tests are negative. APT detects a delayed reaction that is not triggered by the specific allergic antibody IgE. This so-called “cell-mediated” type of reaction involves a separate part of the immune system.

During the test, your doctor will use special tape to place a prepared panel of food extracts on your back. You will be required to keep this panel dry and in place for 48 to 72 hours. Your doctor will schedule a return appointment so the tape can be removed. 

Treatment

When you know what foods you are allergic to, the best approach is to eliminate these foods from your diet and have emergency medications like epinephrine, which can reverse symptoms of anaphylaxis, on hand at all times in case of accidental ingestion and allergic reaction.

It’s important to seek emergency medical care immediately after using an EpiPen or Auvi-Q (epinephrine). Wearing a medical alert ID necklace or bracelet indicating your food allergies is also recommended.

Your healthcare provider may prescribe medications to help with allergic reaction symptoms, including:

• Antihistamines, which can reduce itching or congestion
• Corticosteroids, which can reduce swelling if you have a severe allergic reaction

Summary

Food allergies occur when your body overreacts to the proteins in specific foods. Several major foods can cause allergies, including milk, eggs, fish, shellfish, tree nuts, wheat and grains, and soybeans. It's important to avoid these foods if you have an allergy to them. You should also have emergency medicine like epinephrine close by in case you accidentally eat anything you are allergic to and experience an allergic reaction.

A Word From Verywell

Not all food allergies are life-threatening. Most times, symptoms can be mild and uncomfortable. If you have a family history of food allergies, asthma and experience adverse reactions after eating certain foods, check if you have any food allergies and get tested. Once you have a diagnosis, follow your doctor's recommendations on treatment and what foods you’ll be able to consume safely.