Monday, June 30, 2014

Are Allergies Increasing?

My first reaction was, "Probably not.  More like increasingly neurotic parents turning little things into disasters."  But to my surprise, a number of studies do show that various types of allergic reactions are on the rise in Western nations.  This study shows an 18% increase in food allergies among under 18s in the U.S. from 1997 to 2007.  This study, while showing no increase in Switzerland adolescents after 1992, indicates that there was a definite increase before then.  Similarly, this study of German children showed a large increase in the latter half of the 20th century, but nothing since the start of the new century.  This study of a variety of allergic reactions in British children shows a noticeable increase in many forms of allergies, although perhaps decline in the last few years.  What was especially startling, however, was this:
Among adults, national surveys have found that there has been no recent increase in the population geometric mean total IgE (45 in men and 30 in women in 1995–6 and 42 in men and 27 in women in 2001).
Why allergies increasing among children, but not adults?   It isn't like the children don't generally grow up to be adults.


Jon said...

The nightly news had a "preview" last night about the "epidemic" of peanut allergies in children. Didn't get a chance to catch the show, but I commented to my wife how strange it is how many people now have food allergies. When we were growing up, you never heard of a peanut allergy, in my kids generation, it was an occasional thing we'd see at the day care, and now it's an epidemic? Same thing with gluten allergies. What in the world is going on? Can the alarmists really be right about GMOs?

Unknown said...

I believe it has been linked to exposure to the outdoors and various potential allergens.

If kids sit inside all day rather than going out to play, their immune systems don't develop correctly.

Clayton Cramer said...

Jon: the problem grew dramatically worse before GMOs -- and now the problem has stopped increasing, now GMO food is actually making it to market.

I fear that the other explanation--kids not playing outside--might be a factor. Part of why polio became the scourge of the 20th century was that children were not exposed to as many pathogens growing up in relatively clean societies.