You can't drink milk because it gives you an upset stomach. Whenever you eat shrimp, your skin starts to itch. Are you allergic? Intolerant? Is there a difference? If you're like most of the population, you may have no clue. A study just published in the Annals of Allergy, Asthma & Immunology finds that while most of us are aware that a food allergy can be fatal and can easily recognize the symptoms, a majority of Americans can't tell the difference between a food allergy and food intolerance, and don't understand the treatment options available.
It might not seem like that big of an issue, but food allergies can be extremely serious, even fatal, while food intolerance simply causes discomfort. "I think that people don't appreciate how a true food allergy, because it is serious, affects all aspects of life," says Scott H. Sicherer, MD, associate professor of pediatrics at Mount Sinai School of Medicine and author of "Understanding and Managing Your Child's Food Allergies" (Johns Hopkins Press, 2006). "Imagine not being able to eat milk or eggs. For a child this affects all social situations (birthday parties, trick or treat, Thanksgiving, etc), school, and camp. It is a 24-hour, seven-day-a-week issue."
If something you eat seems to make you sick, here are a few ways to tell the difference between food allergy and food intolerance:
Food allergy
What it is: A food allergy happens when the immune system mistakenly attacks the proteins in a food, says Dr. Sicherer. When the body mistakes a food item, such as a peanut, as a foreign substance, it starts to produce antibodies to fight that substance. The next time the body encounters that food, the antibodies sense it and signal the immune system to react, causing hives, swollen tongues or lips, dizziness, fainting, and in severe cases, death. "The symptoms can happen quickly after eating the wrong food," he adds. "Some people are very sensitive, and a trace small amount of the food can trigger a reaction."
Common allergens: For children, the three most common food allergens are milk, peanuts, and eggs. According to the study results, many people incorrectly think that kids with milk allergies can drink low-fat milk. The most common allergen in adults is shellfish.
Other misconceptions: Based on the study responses, about 40 percent of people think that allergies don't go away as kids get older. About 55 percent of people think there's a food allergy cure, and 30 percent believe there's a daily medication available for people with food allergies. All are incorrect: Allergies can disappear with age. In fact, milk allergies are the most common allergy that kids outgrow, says Ruchi Gupta, MD, MPH, assistant professor of pediatrics at Children's Memorial Hospital Northwestern School of Medicine and lead author of the study. However, the only way to effectively deal with allergies while you have one is to avoid the offending food. To see if a food allergy has gone away, check with an allergist for testing.
Food intolerance
What it is: Unlike food allergies, food intolerance has nothing to do with your immune system. People who can't tolerate foods lack some component in their digestive systems that's needed to digest the food; for instance, lactose intolerance occurs in people who lack the digestive enzyme lactate. "Food intolerance is not life-threatening, but it creates discomfort," says Dr. Sicherer. Symptoms tend to be related to digestion, including cramping, diarrhea, gas, and bloating. But some food additives can cause rashes or asthma attacks, which can be confused with allergy symptoms. Some people can tolerate small amounts of a food they're intolerant to.
Common food intolerances: Celiac disease, a condition in which people can't digest foods containing wheat gluten, is one of the more common forms of food intolerance, and "most of the world's population actually has some degree of lactose intolerance," says Dr. Sicherer. Food additives, such as dyes in food and sulfites in wine, often trigger an intolerance that's confused with an allergy, says Dr. Gupta. (Given the dangerous nature of food allergies, it's better to err on the side of caution in such cases.) If you're not sure which food is triggering your digestive problems, eliminate all the suspects from your diet and add them back in gradually.
Other misconceptions: Some food intolerances can be treated. "You can take a pill that has lactate," the missing enzyme in milk intolerance, says Dr. Gupta. Beano, sold to prevent beans and vegetables from causing flatulence, provides a missing enzyme needed to digest those foods.