When your body misfires against seemingly innocent foods, could it be the start of a food allergy or an intolerance?
IN A TIME when gluten-free options grace menus, schools are nut-free zones, and people boast about their dairy-free diets, we’re more aware than ever about food allergies and intolerances. But they are two very distinct conditions.
“A food allergy is an immune response where the body produces antibodies called IGE in response to a particular protein in the food,” explains Georgiana Sanders, MD, an associate professor at the University of Michigan Mary H. Weiser Food Allergy Center. The body attacks these typically harmless proteins, triggering an allergic reaction, which can appear within seconds or hours of exposure. To be diagnosed, you must exhibit symptoms such as hives; wheezing; runny nose; itchy eyes; or lip, throat, or tongue swelling; plus a positive blood test or skin prick showing the presence of antibodies.
Fifteen million Americans have food allergies, and 9 million of those are adults. And it’s not your imagination: Allergies are on the rise in children and adults. Food allergies in kids spiked by 50% between 1997 and 2011, according to the Centers for Disease Control and Prevention. Preliminary research presented in 2017 at the American College of Allergy, Asthma, and Immunology found that 45% of adults with food allergies develop them in adulthood, most commonly to shellfish and tree nuts. There are two plausible theories to explain this increase in food allergies: the hygiene hypothesis (in essence, we live in a too-sterile environment), and the idea that delaying introducing certain foods to infants (particularly peanuts) may prevent budding immune systems from maturing properly.
A food intolerance (also called a sensitivity) occurs when you have difficulty digesting a food, leading to gas, abdominal discomfort, or diarrhea, but there’s no immune reaction or antibodies produced. The most common intolerances are to lactose (a sugar found in milk), gluten (a protein found in wheat), and certain complex carbohydrates (from beans and cabbage). It’s best to talk to your doctor if you suspect a specific food is routinely causing digestive woes. Avoiding foods unnecessarily can lead to a nutrient shortfall in your diet, particularly if you remove multiple foods in a blind effort to heal symptoms. If you do have to steer clear of a type of food—for instance, dairy—a dietitian can help you plan your diet so that you’re getting other sources of calcium and vitamin D (like fortified nut milk).