Food allergies: The stakes are too high for myths and pseudoscience

[HuckleB]

http://sciencebasedpharmacy.wordpress.com/2013/09/13/food-allergies-the-stakes-are-too-high-for-myths-and-pseudoscience/#more-5102


"The price of life is eternal vigilance. If you have severe food allergies, that is your reality. Every day, every meal, every bite. Eating is an intrinsic and essential part of what we do and who we are, so the idea that our bodies can rebel violently to everyday foods can be difficult to believe. But it’s real, and the numbers of the severely food allergic are growing. Frustratingly, we don’t know why. While recognized over 100 years ago, the social acknowledgment had lagged. That’s improved in the past decade. Food allergy prevention approaches are now a routine part of travel, school, sports, and the workplace. Peanuts on planes seem to have completely disappeared. The days of lunchbox peanut butter sandwiches are over, with many schools completely banning all peanut-containing products. It is the education system that seems to have become a ground zero for allergy programs and policies, where educators are challenged to ensure that schools are safe environments for all children, some of whom have long lists of food allergies.

While 30% of the population believes that they have a food allergy, the actual prevalence is about 5%. Allergies are a product of our immune systems, with multiple biochemical pathways triggered in response to a specific antigen. “Allergy” can describe mild skin reactions and respiratory distress, right through to life-threatening reactions. The majority of food-related allergic reactions are not life-threatening. Anaphylaxis is the term that describes the most rapid and severe immune response, which can occur in response to a drug (the most common cause of anaphylaxis), an insect, or food. Food-allergy anaphylaxis is rare, occurring in one to 70 per 100,000 of the population. Eight food cause over 90% of anaphylactic reactions: milk, eggs, peanuts, tree nuts, fish, shellfish, soy, and wheat. Reactions may involve multiple body systems (gastrointestinal, skin, respiratory) including breathing difficulties and swelling of the throat. Anaphylaxis is estimate to have fatality rates of 0.7-2%. Death occurs due to upper airway obstruction, vascular fluid shifts, and depressed heart function. The risk of anaphylaxis, and how quickly it can appear in any individual with a history of allergy, is difficult to predict, and can be influenced by age, the type of allergen, the extent of exposure, and underlying illness like asthma.

Evaluation of anaphylactic food allergies involves a number of diagnostic tools including skin testing, in-vitro tests, and food challenges. There is no single diagnostic test. Different tests may be used depending on the patient’s history of reactions. All of these tests have different risks and benefits and must be performed under the supervision of an allergist, where immediate access to resuscitation equipment is available. Food allergies in children can resolve over time, like milk and egg. Tree nut and peanut allergies, however, are more likely be life-long conditions.

Given the life-threatening nature of some food allergies, you’d think there would be no room for myths or pseudoscience. You’d be wrong. Confusion and misinformation abounds. There is the unfortunate tendency to label any sort of negative reaction to any substance as being an “allergy”. I see this frequently when speaking with patients about their medical history, who rhyme off a long list of drug “allergies”, which more frequently describe intolerance, like diarrhea to antibiotics, or nausea and drowsiness from narcotics. Then there are “allergies” pulled out of thin air. The current fad food “allergy” is gluten, a self-diagnosed condition in which gluten is believed to be some sort of dietary toxin – which must be distinguished from (1) the person with the documented anaphylactic wheat allergy and (2) those with celiac disease, an auto-immune response to gluten that requires absolute avoidance (but does not cause anaphylaxis if ingested). Capitalizing on the confusion about allergies and intolerances are alternative medicine providers, who offer their own definitions of allergies, and (conveniently) their own cures. The result is widespread confusion about allergies, and worries that we’re seeing too many nonexistent allergies while raising the risk we’ll miss the truly life-threatening ones. As a parent of young children, I sympathize with the staff at my local school, where each year means a new group of parents who grumble about the school’s policies in place to minimize the risk of allergic reactions. Eggs, peanuts and milk are the most common allergies, but peanuts and tree nuts cause more fatal anaphylactic reactions, so restrictions on those food products are more common. Tragic deaths have driven systems to implement new policies. What’s worse, severe reactions are more common in children and children and young adults are at greater risk of a fatal reaction.


..."


A very good review of the topic, IMO.

[xchrom]

1. du rec.