What's a Food Allergy -- and What's Not? | Body Stuff with Dr. Jen Gunter | TED

People often confuse food allergies and food intolerances.

But it's important to know the difference

because they each require a different treatment.

So what is the difference?

[Body Stuff with Dr. Jen Gunter]

A food allergy is your body's immune system

responding to specific proteins in certain foods.

For instance, in shellfish,

one of the triggers for allergic reactions is a protein called tropomyosin.

And with peanuts, it can be a reaction to one of its many proteins.

When a food particle enters the body of someone who's allergic,

the body's immune system perceives it as a problem, an invader.

Just as your body might respond to a virus as a threat,

with food allergies,

part of your immune system sees the protein of the food as a threat.

The allergic reaction can be thought of as a disproportionate

and inappropriate response from the immune system to the food.

Allergic reactions can range from being mild:

tingles in the mouth, hives and rashes,

to being extremely severe, like having trouble breathing.

And they can even be life threatening.

Allergic reactions, with some exceptions,

almost always happen quickly,

within 30 minutes of eating or exposure to the food.

A food intolerance, on the other hand,

is usually our body having trouble digesting certain foods.

Unlike allergies, food intolerances are not related to the immune system.

For instance, being lactose intolerant

means you don't have enough of the enzyme that breaks down the lactose in dairy.

Intolerance to certain foods can often result in digestive issues,

including bloating, diarrhea or just generally feeling unwell.

Intolerance to food can happen pretty quickly too,

but could also show up in the next few days.

In other words,

if you experience unpleasantness from something you've eaten a day before,

most of the time it's not an allergy.

There's a third kind of reaction

that's neither an allergy or an intolerance.

For example, celiac disease is an autoimmune condition

triggered by eating foods containing gluten.

Celiac disease may share some similar symptoms to a food intolerance,

such as bloating or belly pain.

But unlike celiac disease,

food intolerances don't damage the small intestine.

So with all these real but nuanced differences,

what's the best way to get a proper diagnosis?

Don’t get one of those “do-it-yourself at-home food-sensitivity” kits.

Those tests are not scientifically proven to do what they purport to do,

and they aren't reliable diagnostic tools.

If you wonder whether you have an allergy or an intolerance

or celiac disease,

talk to your doctor.

They'll be able to recommend the right course of action.

And in the case of food allergies, an allergist is your go-to person.

The two common ways they'll be able to diagnose you

is by taking a really good food history

and giving you an oral food challenge

by giving you certain foods and seeing what happens

in a medically safe and controlled environment.

An allergist can also come up with a plan

in case you're exposed to a food you're allergic to

and may even be able to recommend treatments for some of those allergies.