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Making Sense of Allergies: A humble & honest guide to clarify the noise surrounding allergies

Posted on 3rd July 2015 by

Evidence Reviews
allergy testing

Why allergies bother me?

Allergies is surrounded by a mist. Every day, we come across with all sorts of fussy and overwhelming statistics, information and advertisements, telling us how many allergens are threatening our health. Much of the conflicting information coming from the professional and “popular expert” confuses our understanding of allergies, instead of informing us a better life-choice. Can you be sure about the answers of the following statements?

“To reduce exposure of allergies, shy away from man-made chemicals and desiring for more natural life!”
“E-number and preservatives in food cause allergies!”
“Avoidance paradigm is good for children’s diet.”
“Hypoallergenic means free of allergen.”

Whilst we are not certain about allergies, we tend to over-react and become “worried well” people. “A study of 949 children in the Isle of Wight found 34% of parents reported food allergies in their children but only 5% were found to have an allergy” (p.8). Now, it is high time we navigated our way to properly understand allergies.

Then what can I read?

If you are interested in knowing allergies, the good news is that this is a guide worth your time to read through. It was released last month by Sense About Science. This guide draws on the collective expertise-driven resources from six organisations of allergy specialists, including the British Society for Immunology and Cochrane Airways.

What I should know about allergies?

The guide addresses different misconceptions in relation to allergies, based on the reviews of relevant studies worldwide. To highlight, I will illustrate three concepts of allergies with reference to the guide marked with the page number.

Allergies are a health concern.

Allergies occur when body defense has gone wrong. Asthma, rhinitis, food reactions, eczema, rashes and swelling and drug reaction are some examples of allergies (p.12). Though allergies cause only discomfort most of the time, anaphylaxis can cause breathing difficulty and/or low blood pressure, which are life-threatening conditions. We should be concerned with allergies as the latest scientific evidence still cannot predict or explain the development of anaphylaxis (p.12).

Food allergies are different from food intolerance.

The mechanisms operated in food allergies and food intolerance are different, and therefore, our responses to both are different. There usually exists a threshold for the intake of intolerable substances in our diet, whereas allergies will occur with an exposure to a trace amount of allergens (p.14). Moreover, it is not necessary for you to expose to the allergic substances in ordern to acquire the specific allergies. Moreover, cross-reactive allergies are possible; for instance, if you are allergic to grass pollen, you are more likely to be allergic to peaches and/or oranges as well (p.13).

Allergies concern our immune systems (p.10). Our white blood cells produce antibodies after identifying threat, such as bacteria and virus (p.10). In the next encounter of the threat, the antibodies in the blood will trigger cells to release inflammatory substances for a defensive purpose. However, when immune system mistakenly produces antibodies against a harmless substance (an allergen we call), we say that the unnecessary response, which manifests itself in various forms (e.g. itching, sneezing) an allergic reaction (p.10). By contrast, Food intolerance is nothing about the immune system (p.14).

Allergies can be life-long.

Allergies like nut allergy are usually life-long.  Also, the severity of allergies will not necessarily increase with the number of encounters. There are lots of examples of people outgrowing some allergies, yet the underlying reasons have yet been understood (p.12).

What does it mean to me?

The guide tells you that the best scientific knowledge about allergy is far from exhaustive. All the evidence points to the inconsistencies in the existing literature. For academics, there is a pressing need for continuous assessment and evaluation of the evidence. Results of evidence should not be inappropriately generalized given the limited established facts.

For members of the public, this is not a disappointing fact that we do not know much. The challenge now facing us will be how to be alert the possible risks of allergies in our daily life while not being the “worried well” population. It won’t be an easy assignment. People are inclined to pick up on uncertain things, and consumer markets are keen on market alternative products to “relieve us of the catch-all anxiety”.

And this is the link to the Sense About Science guide!


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