An increasing number of kids say they have allergies to food when they actually don’t, according to a new study released by Umeå University in Sweden.
Also shown by the study, only 12.5 percent of those kids’ proclaimed allergies are real. In order to explain why and how this came to be a problem, it is important to look at how food allergies are diagnosed, which is through allergy skin and blood tests. Bob Lanier, the executive medical director at the American College of Allergy, Asthma and Immunology at the University of North Texas HSC, said that while there are multiple ways to examine food sensitivities, they don’t all have the same level of assurance.
“Blood tests called specific IgE (immunoglobulin E) tests are usually pretty accurate. Many times, erroneously small positive tests result in drastic dietary avoidances,” Lanier said. “Skin tests are very accurate when applied and interpreted by experts. Blood test and skin tests both complement each other—blood test are not very sensitive, and skin tests can sometimes be too sensitive.”
Despite the IgE tests’ accuracy, Lanier said alternative blood testing, which looks at the antibody called G, is on the rise. This form of testing is known for giving almost all positive results to its users, which results in unneeded dietary changes. Although G blood testing is on the pricier side of the scale and not covered by insurance, it is still popular with the public for almost always providing positive results, though they may be false.
Lanier claims the word “allergy” is not always used correctly. When allergists use it, it pertains to IgE, an immunologic reaction that involves the allergic antibody. When others use the term, however, they often confuse it with the release of the chemical histamine. He said allergically released histamine can be more grave since it may involve unavoidable factors such as pollen and certain foods.
“The actions of histamine are what most people view as allergic. But indeed there are many ways histamine can be released other than allergy,” Lanier said. “For example, if you throw a handful of black pepper in someone’s face, that will cause histamine release and temporarily duplicate the symptoms of allergy. But pepper is an irritant, and 100 percent of people will have a reaction that will seem allergic but not involve the allergic antibody.”
Jama Lambert, the director of education at Cyrex Laboratories for clinical immunology in Phoenix, Arizona, defines an allergy as “an immediate, hyperimmune response that results in anaphylaxis, or hives, or swelling of the lips or tongue soon after eating the offending food.” Lambert said these immune reactions affect only about one to three percent of the U.S. population, although some foods have a higher allergy occurrence.
“The more common immune response is a delayed immune reaction caused by IgG and/or IgA and is identified by testing blood. A delayed immune response usually referred to as ‘sensitivity,’ or ‘intolerance,” Lambert said, “and can result in bloating, diarrhea, constipation, achy joints, brain fog, general inflammation and a host of other symptoms depending on the culprit food. The symptoms are not immediate and most often do not show until the day after eating the food.”
Luckily for senior Molly Sparkes, allergy testing helped her detect and treat nine of her previous 43 allergies. Sparkes did find out she is allergic to apple skins about two years ago after noticing that her mouth burned and itched after she ate them. Her doctor was able to confirm the allergy, so she wasn’t tested for it. Sparkes was, however, tested for allergies in general and found it to be life-altering. She got skin tests for the first time during her sophomore year and found that she was allergic to 43 things, including various trees, grasses, cats, molds, dusts, rabbits and the different seasons of the year.
“I started receiving two shots a week and the difference was immediate. I could actually breathe during the spring. I wasn’t staying home sick as often. I wasn’t afraid to go outside. Even though I know the shots don’t work on everyone, I cannot stress enough how much it is worth to try,” Sparkes said. “I now take two shots every other week and have gone down to having only 34 allergies. My allergies affected my school attendance, how active I was and my quality of life. I think the tests are very accurate at detecting allergies, and I’m forever happy that I was tested and sought treatment.”
Like Sparkes and Lanier, Lambert believes people should get be tested for allergies, but said the best way to test food immune reactivity is through the elimination provocation diet. This tiring process is exactly what is sounds like — eliminating specific foods from one’s diet that seem to be causing allergies. She said blood and/or skin testing are the next best options, as long as the correct test is chosen.
“When choosing a test, the best practice is to order one that tests foods that match what and how the patient consumes them. A big problem with current lab tests, Cyrex being the exception, is they are assessing immune reactivity to raw foods,” Lambert said. “How many of your friends eat raw potatoes and raw hamburger? On such a test, if you get a positive to beef, you really don’t know if you react to cooked beef, which is what you eat. At Cyrex, we test IgG and IgA reactivity to foods the way in which most Americans eat them. For example: raw lettuce, raw broccoli, cooked broccoli, raw tuna, cooked tuna, cooked lamb.”
Another difference between an actual food allergy and a food sensitivity, Lanier said, is that an allergy can cause a potentially fatal reaction called anaphylaxis, while a food sensitivity will likely not. Some people simply find certain foods irritating, but those foods are not dangerous. As a child, Lanier ate so much baloney that he got sick from it, and, to this day, is nauseated by it. This is called a food aversion. Other food reactions that do not constitute valid allergies are lactose sensitivity and feeling anxious after drinking caffeine. In fact, actual food allergies are fairly uncommon.
One sign of a true food allergy is when people with a pollen allergy are also sensitive toward foods in the same plant family.
“People who were very allergic legitimately to ragweed, for example, may have trouble with plants from that same plant family. In that example they may have difficulty with bananas, melons, and avocado,” Lanier said. “Eating those foods may cause [itching]. While it rarely causes anything more, it’s called oral allergy syndrome. We don’t generally think of it as being dangerous at all.”
Fortunately, most people who may think they are allergic to a food are really not. That has, however, caused much confusion among the public.
“The problem is that people refer to delayed immune reactivity to food as ‘allergy,’” Lambert said, “when the majority of people who do not feel well after eating a specific food actually have a food sensitivity or intolerance.”
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Most reported allergies not real, study finds
April 28, 2016
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