by Katherine Butler, Mother Nature Network
The worst thing most people suffer from a meal is a wicked case of indigestion. But for some, eating the wrong thing can cause hives, swelling, vomiting and even death. As many as 12 million Americans have a food allergy, including 1 in every 13 children under the age of 18, according to the Food Allergy Initiative. Food allergies occur when the immune system mistakes a food protein as a threat and attempts to protect the body by releasing histamines and other chemicals into the blood. A food allergy is different from food sensitivity or intolerance, which does not involve an immune system reaction. You can be born with a food allergy, or it can develop over time. These eight foods are the root of 90 percent of all food reactions, according to the Food Allergy & Anaphylaxis Network. For an overview of the eight allergens, read on. (There are plenty good sources of information on the Web about allergies, but some of it offers conflicting advice. For the best outcome, consult your doctor.)
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Milk allergies are considered the most common food allergy in children. This generally involves cow's milk, but milk from buffalo, goats and sheep also can cause a reaction. Milk allergy symptoms include wheezing, vomiting, hives and digestive problems. According to the Mayo Clinic, milk rarely involves a life-threatening anaphylaxis reaction, which is a whole-body reaction that can cause airways to dangerously tighten. But allergy experts warn that, to be safe, it is important to know that any food, at any time, can cause a severe reaction.
Since eggs are such a common ingredient in foods, living with an egg allergy can prove challenging. Most people who are allergic are sensitive to the proteins found in egg whites, though some are irritated by the proteins found in the yolk. Symptoms of an egg allergy include wheezing, nausea, stomachache and hives, according to the Mayo Clinic. Generally, an allergic reaction to eggs occurs a few minutes to a few hours after eating them. This is the second most common food allergy in children, affecting anywhere from 1.5 percent to 3.2 percent of children, according to the American Academy of Allergy, Asthma, and Immunology, and about 68 percent of egg allergies are outgrown by age 16.
Peanut allergies are not as common as you would think, with about 1.2 percent of children affected, according to statistics from AAAI, and about 20 percent of children outgrow it around the age of 6. Reactions can range from a mild annoyance to a severe anaphylaxis. Much has been written about peanut allergies and air travel concerns, but the Department of Transportation has left it to the airlines to make their own decisions. People who have had a mild reaction should take precautions.
Soy, a legume like its cousin the peanut, is a common allergen among infants. Most children outgrow the allergy, but for some, it may persist into adulthood, according to the Mayo Clinic. Symptoms are typically mild, including hives or an itchy mouth, but some sources suggest they can be as extreme as acne and anaphylaxis. Soy can be difficult to avoid, as it is found in processed meats, baked goods and many desserts.
Can you enjoy a good salmon steak? Not if you are one of 7 million Americans, or 2.3 percent of the population, who are allergic to fish and shellfish. Fish is a lifelong allergy, and almost half of people with fish allergies first experience symptoms as an adult, which can include swelling, itching, cramps, wheezing, heartburn, dizziness and eczema. Determining a fish allergy can prove complicated, as people may be allergic to one kind of fish but not another. Fish can lurk in the strangest places, including salad dressing, Worcestershire sauce, meatloaf and barbecue sauce.
Wheat allergy is another common affliction, and can cause stomach upset, eczema, allergic rhinitis, asthma and anaphylaxis. Avoiding wheat isn't easy, as many unsuspecting products contain it, including ice cream and ketchup. Wheat contains the proteins albumin, globulin, gliadin and gluten, and wheat allergies are often confused with gluten sensitivity. While gluten is found in wheat, the abnormal immune reaction people experience toward it is called celiac disease.
While many allergies first appear in childhood, an aversion to shellfish often crops up in adulthood. Along with peanuts and tree nuts, shellfish can produce some of the strong anaphylactic reactions that are considered most dangerous to people with food allergies. There are two kinds of shellfish: crustaceans, like shrimp, crab and lobster, and mollusks, like clams, mussels, oysters and scallops. People may be allergic to crustaceans or mollusks or both. Doctors generally recommend consulting a medical professional to help determine tolerance. Further, if you are allergic to shellfish, that doesn't mean you will be allergic to bony fish.
As many as 1.8 million Americans are allergic to tree nuts, which are among the leading causes of fatal reactions to food including anaphylaxis. Tree nuts can be broadly defined to include cashews, Brazil nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios and walnuts. (Coconuts and almonds cause some confusion. Technically, they are drupes, but the FDA has classified them - and many other items - as tree nuts.) Tree nuts can be found in salad dressings, honey, pancakes, pasta, veggie burgers and even in barbecue sauce. They are not to be confused with peanuts, which are legumes.