This article is brought to Earth Eats courtesy of Eric Sonstroem at A Moment of Science.

Do you know what a food allergy is? A study several years ago showed that twenty-five percent of adults believe they have food allergies. According to doctors, the number of adults who actually have food allergies is more like one or two percent.

Intolerance Or Allergy?

One reason some people think they have a food allergy when they really don't is because they're confusing a food intolerance with an allergy.

Food Intolerance

A food intolerance--like the common lactose intolerance to milk--occurs when the body lacks certain enzymes to suitably digest a type of food.

If you are lactose intolerant, you might experience gas, abdominal pain, and diarrhea from drinking milk or eating ice cream because your body can't digest the sugars in the milk.

Food Allergy

A true food allergy has little to do with digestion-- instead, it's an immune system response. Your body treats the food like a foreign invader, and manufactures antibodies to fight it.

Any contact with the food--even touching it or kissing someone who has recently eaten it--can trigger allergic responses such as hives, asthma, vomiting, swelling, and so on.

What Can Happen?

While a food intolerance can be a painful nuisance, a true food allergy can be deadly. If you are severely allergic to peanuts, for example, eating only half a peanut can lead to asphyxiation and death.

While only one or two percent of adults have true food allergies, about five percent of children do, usually outgrowing them by around age four. That's why parents should be especially cautious--and especially observant--when introducing new foods to their toddlers.

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