January 2019

FOOD ALLERGIES VS INTOLERANCE:  WHAT IS THE DIFFERENCE? 

The two terms tend to be used interchangeably but knowing how they differ can help

you manage your symptoms, prevent potential nutrient deficiencies, get the right

treatment, and feel your best.

In a time when gluten-free options grace menus, schools are nut-free zones, and people boast about their dairy-free diet, 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.   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.  Preliminary research has 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 (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 properly maturing.

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.  Unnecessarily avoiding foods 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 are getting the nutrients found in dairy foods from other sources in your diet.

Uncovering allergies and intolerances isn’t as cut-and-dried as it appears.  Here are the tests to try and to skip when it comes to finding out what’s going on inside.

IgE Antibody Test: The gold standard for allergy testing, but false positives are common.  Or antibodies show up after you eat a food, but there are no symptoms (thus it’s not an allergy), this could be the body reacting to factors like pollen.

Skin Testing:  A common test that involves injecting the skin with a tiny bit of the allergen.  Positive reactions will appear as a “wheal and flare” (a raised red area) that’s bigger than a control prick of salt water.

At-Home Testing: you can buy kits online that claim to provide insight on which foods trigger allergies or intolerances, but these tests, have not been proven to be effective and may lead you to unnecessarily eliminate foods.

Food Elimination: If you suspect an intolerance, your doctor may suggest eliminating the suspected foods for six weeks.  Add one food back per week and record any symptoms you experience to reveal any telling patterns.

Jessica Migala