Understanding the 8 most common food allergies Food allergies have become an important topic in recent years for many reasons. Their incidence is on the rise, affecting 30% of adults and 40% of children. People can be allergic to almost anything, but 8 allergens are the most common. What is an allergy? When your body is exposed to an irritant (known as an allergen) such as pollen, it attacks it. When it happens, we usually don't even notice. Sometimes, if the allergen is in excess or your body is particularly sensitive to it, this immune response kicks into gear. Your eyes water, your nose is stuffy, or you develop an itchy rash. Some allergens cause life-threatening reactions, such as anaphylaxis, which leads to a sudden drop in blood pressure and narrowing of the airways. Foods can also act as allergens. When someone is allergic to a food, they cannot eat it at all. Some allergies are so severe that people cannot even be near the irritant because inhaling or touching it could ...