There is no fixed number of food allergies. Any food containing protein can theoretically trigger an allergic reaction, and researchers have documented allergic responses to more than 170 different foods. In practice, though, a small group of foods causes the vast majority of serious reactions, which is why governments maintain official lists of “major” allergens for food labeling purposes.
The 9 Major Allergens in the U.S.
The FDA recognizes nine foods as major allergens, meaning they must be clearly identified on all packaged food labels. These nine account for the overwhelming majority of serious allergic reactions in the country:
- Milk
- Eggs
- Peanuts
- Tree nuts (almonds, walnuts, pecans, and others)
- Fish (bass, flounder, cod, and others)
- Crustacean shellfish (crab, lobster, shrimp)
- Wheat
- Soybeans
- Sesame
Sesame was added as the ninth allergen in January 2023 under the FASTER Act. Before that, manufacturers had no obligation to call it out on labels, despite it being a well-known trigger for severe reactions.
The EU Tracks 14 Allergens
The European Union requires labeling for 14 allergen categories, five more than the U.S. list. The overlap is substantial, but the EU also includes celery, mustard, lupin, molluscs (mussels, oysters, squid, snails), and sulphites. These foods cause enough reactions in European populations to warrant mandatory disclosure. The difference between the two lists illustrates that “how many” food allergies matter depends partly on where you live and what people commonly eat.
Beyond the Official Lists
Allergic reactions have been documented to foods that appear on no mandatory labeling list. Kiwi, corn, rice, banana, avocado, and various spices all cause confirmed allergic responses in some people. These reactions can range from mild itching to full anaphylaxis. The reason they’re not on official lists isn’t that they’re harmless. It’s that they affect far fewer people than the major allergens do.
One common but underrecognized pattern is oral allergy syndrome, where people with seasonal pollen allergies react to certain raw fruits and vegetables. The proteins in these foods resemble pollen proteins closely enough to confuse the immune system. Among adults allergic to birch tree pollen, 50 to 75% experience tingling or itching in the mouth after eating foods like apples, cherries, carrots, or hazelnuts. People with grass allergies may react to peaches, celery, tomatoes, and melons. Ragweed allergy can cause symptoms with bananas, cucumbers, and zucchini. Cooking the food usually eliminates the problem because heat breaks down the proteins responsible.
A Newer Allergy: Red Meat
Alpha-gal syndrome is a food allergy that doesn’t fit the traditional mold. It’s triggered by tick bites, not by repeated food exposure. When a lone star tick bites a person, it can transfer a sugar molecule called alpha-gal into the bloodstream. The immune system flags that molecule as a threat, and because alpha-gal is naturally present in most mammalian meat, the person develops allergic reactions to beef, pork, lamb, and other red meats.
The CDC estimates that as many as 450,000 people in the U.S. may be affected, with over 110,000 suspected cases identified between 2010 and 2022. Reactions are often delayed, appearing three to six hours after eating, which makes the allergy notoriously difficult to diagnose. Alpha-gal syndrome is a reminder that new food allergies can emerge from unexpected sources.
How Common Food Allergies Are Overall
In 2024, 6.7% of U.S. adults reported having a diagnosed food allergy, according to the National Center for Health Statistics. That translates to roughly 1 in 15 adults. Women are more likely to have a food allergy (8.3%) than men (5.1%), and younger adults are affected more often than older ones: 7.4% of adults ages 18 to 44 compared to 4.7% of those 75 and older. Black adults had the highest rate at 9.9%, compared to 6.4% for White adults, 5.5% for Asian adults, and 5.4% for Hispanic adults.
Food allergy rates in children tend to run even higher, with previous national surveys consistently placing the figure around 8% of kids. The consequences can be severe. In New York City alone, hospitalizations for food-related anaphylaxis more than doubled between 2000 and 2014, rising from about 16.5 per million people annually to 34 per million. Emergency department visits showed an even sharper increase.
How IgE Reactions Work
Most food allergies involve an immune protein called IgE. Normally, IgE helps the body fight parasites. In a food allergy, IgE mistakenly identifies a harmless food protein as dangerous. The next time that food is eaten, the protein enters the bloodstream during digestion, and IgE triggers the release of histamine throughout the body. That’s why food allergy symptoms can show up in so many places at once: hives on the skin, swelling in the mouth and throat, vomiting, difficulty breathing, and in the most serious cases, a drop in blood pressure and loss of consciousness.
Not all food allergies work through IgE. Some involve different parts of the immune system and tend to produce slower, primarily digestive symptoms. These non-IgE reactions are especially common in infants and young children and are harder to diagnose because standard skin-prick and blood tests look specifically for IgE antibodies.
Which Allergies Children Outgrow
The likelihood of outgrowing a food allergy depends heavily on which food is involved. Up to 90 to 95% of children eventually outgrow milk and egg allergies, often by school age. Peanut allergy is far more persistent: fewer than 20% of children outgrow it. Tree nut, fish, and shellfish allergies also tend to last into adulthood. For families managing a child’s food allergy, the specific allergen matters enormously for long-term planning.
Allergists typically monitor immune markers over time and may recommend supervised food challenges to determine whether a child has outgrown an allergy. The process is gradual, and tolerance can develop at different ages depending on the individual.