Food allergy and food intolerance are both the body’s reactions to some ingredient in food. however, they affect different body systems. when a person is allergic to a food, his or her body mistakes an ingredient in the food as harmful. a protein in a food is usually the culprit. the body’s immune system tries to attack the food. the most common food allergies are to nuts, milk, soy products, fish, shellfish, and wheat. on the other hand, food intolerance is a digestive system problem. when someone is intolerant to a food, it means that his or her body cannot properly digest or break it down. the food irritates his or her digestive system. lactose (the sugar found in dairy products like milk and cheese) is the most common food intolerance. while some of the symptoms of food allergy and intolerance are the same—nausea and stomach pain—most of them are drastically different. common symptoms of food intolerance are mostly annoying or uncomfortable. they include diarrhea, gas, cramps, bloating, and headaches. food intolerance can be treated with over-the-counter medication. food allergies can be very severe. some people develop rashes or hives, have chest pains or shortness of breath, and in some cases, they can even go into shock. when this happens, a person may not be able to breathe, and his or her blood pressure drops very quickly. food allergies can even result in death. many people have to carry around medicine that is prescribed by a doctor in case they have an allergic reaction. question 19: how is this passage structured? a.) cause and effect. b.) comparison and contrast. c.) definition. d.) classification.