Are Food Allergies Exaggerated? New Study Sparks Questions

May 17, 2010— -- Millions of Americans who believe they have food allergies may be fooling themselves, according to a paper published last week in the Journal of the American Medical Association.

Food allergies can be serious health matters for many, causing sudden, life-threatening reactions that can affect a person's ability to breathe.

But of those people who experience mild symptoms in reaction to a food, many who believe they're allergic are not. While 9 percent of people believe they have allergies, only 5 percent actually do.

It's confusing news for the milllions of Americans who've been tested and treated for allergies, so we invited viewers to submit their food allergy questions ABC's senior health and medical editor:

I ate dairy products for most of my life, but after I turned 45, I started to notice dairy products causing me problems. Now I can't eat any dairy at all since it causes much gastrointestinal distress. Is it common for a dairy allergy to develop later in life? -- Martha

Dear Martha,

Thanks for your question. It is possible you might have a food "intolerance" instead of an allergy. Food allergy occurs when your immune system treats a food as if it were a harmful substance, resulting in an allergic reaction. Food intolerance occurs when your body has a bad reaction to a food, and can't digest it.

For example, lactose intolerance occurs when your digestive tract cannot break down dairy products. People who have lactose intolerance can develop diarrhea, gas, and stomach discomfort after eating dairy products, and this disease can develop later in life. It is important to see your doctor to discuss these symptoms.

My daughter recently had testing done for food allergies. The tests showed that she has several allergies. What is a parent to do when there are so many things on the list that she has never reacted to? -- Holly

Holly,

This is an important question to ask your doctor. The skin and blood tests alone are only right about half the time in diagnosing food allergies. One of the most important things your doctor does to diagnose a true food allergy is to discuss with you what symptoms your daughter has when she eats the foods she tested positive for.

The doctor may also decide to do a food challenge in which a patient is given foods suspected of causing allergy and then monitored to see symptoms develop. It is very important that this is done under the supervision of a doctor and that you do not try to do this yourself -- there is a risk that any of these foods that your daughter tested positive for could cause a severe, possibly life-threatening reaction.