Sudden Rise in Food Allergies Phenomenon

If you grew up in the ’60s or ’70s, you may never have heard the term “food allergy.” Your classmates and playmates probably were able to eat whatever they wanted free from the fear of a reaction. Perhaps your entire school had only one or two kids with food allergies if your school even had a kid with food allergies.
Over the last 20 years, however, the prevalence of food allergy appears to have risen sharply. Researchers can’t pin an absolute number on the increase, because no reliable comparative data over the 20-year period is available — studies being performed today follow different procedures from those performed 20 years ago, so you can’t really compare the numbers. Allergists do, however, have plenty of evidence that points to a dramatic increase in food allergy:

• Evidence gathered over the last 10 years using the same methods show that the prevalence of peanut allergy has doubled in the last 5–10 years.
  
• Anecdotal and clinical evidence shows a significant increase in food allergy. Pediatricians tell me that they see far more food allergy than ever before. School nurses report that while a decade ago they had one or two children in the school with epinephrine prescriptions, they now have 20 or 30. Some of this could be due to what we refer to as a detection bias; that is, increasing awareness about a problem leads to its being diagnosed more efficiently. However, most experts believe that the increase is real and not simply the result of increased awareness.
• Reliable asthma studies show at least a 100 percent increase in the prevalence of asthma (an allergy-related disease) over the last 30 years. The rise in asthma appears to have preceded the rise in food allergy (which is a source of confusion) although experts believe that similar mechanisms likely underlie the dramatic increases in all allergic diseases.

The jump in all allergic diseases across the board suggests that a collection of contributing factors not present 20 or 30 years ago is responsible. Researchers have presented many theories to explain the increase, but the only clear conclusion is that no one, single cause can explain it.