Why are food allergies so common now when they seemed to be rare or non-existent before?


Why are food allergies so common now when they seemed to be rare or non-existent before?

In: Biology

Before we understood the problem, people were just dying. Now that we understand food allergies, we have medicine and prevention.

Food allergies numbers are much higher in the developed world than developing. The reasons aren’t 100 percent understood yet. The basic idea being we are too clean. As children are immune systems developed by being exposed to all kinds of things. But now we deny that by overly processed foods that, aside from what you usually read as a negative, have preseritivies that prevent molds and bacteria growth that our bodies need to fight to become stronger. That is just a simplification. A more specific, huge offender, peanuts contain a protein that our body will think is bad and kick off an immune response. For the past several years mothers were advised to keep peanuts away from infants to keep them safe. The have been rethinking that as it’s being realized that the early exposure is what made the child’s body not fight them.

I don’t think there’s any actual studies done on that. But if a kid in the past came across a peanut and just died, well that was it. There was no medical epinephrine to inject and make you better, so they’d just die. Since kids were dying from everything, allergies were just one of those things. If you made it to adulthood, you likely didn’t have a life threatening allergy. If you had any allergy, it probably made you uncomfortable and you didn’t go near it.

My fiance is allergic to tree nuts. And throughout his childhood, his grandfather would give him nuts. They made his mouth feel strange and so he didn’t like them, but it took a while before they realized he was allergic.

Adults with non severe allergies in the past were likely doing the same thing. ‘Everytime I have shrimp, I get sick. Maybe I should stay away from them.’ ‘Milk makes my stomach hurt, maybe I should stay away from it.’

Two factors are involved, as others have mentioned there is some amount of survivorship bias here. The 2nd factor is the cleanliness paradox, as we live in more developed areas allergic reactions are more common.

It turns out that the immune system grows with us, and learns measured responses to stimuli. If it experiences allergens in a young age it is less likely to overcompensate when experiencing them later in life(which is essentially what an allergic reaction is)

A recent study in Finland found that children who played in natural dirt playgrounds, even if it was indoors, were markedly less likely to develop allergic reactions as they grow older.

I think it’s unknown right now. I saw some Netflix show about different aspects of the food industry that had a whole episode just about allergies. That was maybe 2 years ago?