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Food Allergies: 5 Myths Debunked

How to tell a food allergy from an intolerance or sensitivity -- and what to do about it.

Myth: Food intolerance and food sensitivity are the same thing.

Not true. And neither are the same as food allergy.

Experts say "food intolerance" and "food sensitivity" are often used interchangeably by the public, causing misunderstanding. Add "food poisoning" to the list and people become even more confused.

  • Food intolerance occurs when the body lacks a particular enzyme to digest that food. Two common examples are lactose intolerance and celiac disease, an autoimmune disorder in which the gastrointestinal tract cannot process gluten, a protein in wheat-based products such as cereal and bread.  An intolerant person avoids the foods that trigger a reaction, but these reactions aren’t caused by the immune system and they are not life threatening.
  • Food sensitivity, an understudied area, generally means people have an unpleasant reaction to certain foods; perhaps they develop acid reflux, nausea, or abdominal cramps, but again, these are not immune system reactions, and these reactions do not always occur in the same way when eating the food.

You could also have a bad reaction to food tainted by bacterial contamination or not properly prepared. That's food poisoning. Symptoms often involve diarrhea and vomiting and typically clear up in 24-48 hours.

Myth: If I think I have a food allergy, I should just avoid the offending food.

Reality: If you suspect you have a food allergy, just skipping the food that irritates you isn’t enough.

“There are two major problems with this approach,” Riedl says. “Unintentional food exposures occur, even in the most cautious individuals with true food allergy. The ‘self-diagnosed’ patient is unlikely to be properly prepared to manage this potentially life-threatening reaction, such as use of an Epi-Pen.” Epi-pen and Twinject are injectable forms of epinephrine.

Proper diagnosis, Riedl says, enables patients to understand how best to manage the allergy and eliminates the anxiety, inconvenience, and expense of going at great lengths to avoid foods that do not cause allergies.

More research is also needed to better understand if food allergies can be predicted, particularly during childhood, and why some people outgrow certain food allergies. Insights to both of these issues could help improve prevention and treatment of food allergies.

Fleischer agrees there has been a great deal of undue anxiety around food and food allergies. “Food allergies are definitely being overdiagnosed,” he says. “People are looking for answers to some of their problems and they’re blaming food because food is easy.”

Myth: I only need a blood test to diagnose a food allergy.

Blood tests can also help diagnose a true food allergy by measuring IgE levels and determine whether there’s a true food allergy. However, the new guidelines recommend against the routine use of these tests and making a food allergy diagnosis based on them alone. 

Fleischer warns that blood tests can produce false-positives -- results that indicate an allergy when there isn't one -- in patients who have eczema, asthma, or other types of allergies because those people already have higher-than-average IgE levels.

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