Here is one possible explanation:
www.momsacrossamerica.com/rise_of_allergies_in_the_national_news_but_what_is_the_real_newsIn this NBC news story they are talking about food allergies. They say that there has been a dramatic increase since 1997...
1997 is the first year of widespread implementation of Roundup Ready soybeans and cotton, in other words GMO soy and cotton.