The Rise and Fall of Peanut Allergies

You may or may not have heard that the incidence of peanut allergies has fallen significantly in recent years. Is it due to some new medication? Perhaps a change in how peanuts are grown and/or processed?

Well, the current theory is that the fall in peanut allergies is due to… being exposed to peanuts!

Now, if you have a severe peanut allergy, please don’t go scarf down a bag of peanuts or binge on PB&J sandwiches – you should still avoid peanuts and have an EpiPen handy in case of accidental exposure! As an additional precaution, you might want to consider a “re-set” to reduce your reactivity, such as through acupuncture/acupressure-based allergy desensitization methods.

What I’m talking about though is children who don’t already have a major reaction to peanuts consuming them in moderation.

You see, back in the late 1990’s, about 0.4% of American children had severe peanut allergies. But about a decade later, the incidence had more than tripled to 1.4%! Perhaps this statistical change was somewhat in part to greater awareness and better testing, but the number continued to rise. By 2016, the figure reached 2.2% and it appeared to be still climbing!

And the increase in peanut allergy wasn’t just in the U.S.. Similar increases were seen in other countries.

What was going on?

Various factors were considered, but one major change that occurred before the incidence began to rise rapidly was that medical experts and health officials had started public prevention campaigns encouraging parents to avoid feeding their kids peanuts and peanut-based products until the age of 3. The theory was that very young children still had developing immune systems and that exposing them too early to peanuts was resulting in allergies.

But subsequent research discovered that this was actually counterproductive – kids who had not consumed peanuts before the age of 3 had a significantly higher incidence of peanut allergies than kids who had.

Upon this discovery, health officials reversed course and did away with the peanut avoidance recommendation and the rates of peanut allergy have been falling since – now approaching late 90’s levels.

But why would avoiding peanuts lead to more peanut allergies?

There are various theories, but one of the prevailing ideas is, as with infections from viruses, bacteria, etc.., the immune system functions better with some exposure. When we’re “too clean” and too protective, the immune system doesn’t have the opportunity to develop strategies against infections and it makes us more susceptible to them.

Allergies are different than infections, so the mechanisms are perhaps a bit different. My observation has been that allergies often develop when the immune system is activated to fight an infection, or an inflammatory response has been activated in response to an injury. It seems like there’s a “guilt by association” type of thing going on. The body is engaged in an immune and/or inflammatory response, it senses the presence of a particular allergen, and in an effort to be efficient to deal with future exposures, it develops a reactivity to the allergen.

So, if that’s the case, why would avoidance of peanuts increase the incidence of allergies?

Well, the body is more likely to notice something out of the ordinary in the diet or environment. Low to moderate peanut consumption might be sensed as something normal as opposed to something new to potentially need to react to.

But if a child has had no exposure to peanuts in the first 3 years of life, the body would probably take more notice of them when they first start to be consumed. That might make the “guilt by association” more likely if the child happened to be fighting a virus at the time. And the age of 3 is about the time when kids start to have more interaction with more people (such as in a daycare, for example) and are exposed to more viruses and other infectious microbes. It’s kind of the perfect storm for developing an allergy.

So, the takeaway here is that allergen avoidance may be important for someone who already has a severe food allergy, but avoidance apparently is NOT a good strategy for the prevention of developing food allergies. To have a strong, healthy, normally reactive immune system, it appears that it requires a certain amount of “exercise” with low-level threats to allow it to develop normal reactivity and responses.

Until next time…

George F. Best, D.C.