I don't think so. You are forgetting modern medical science. The infant mortality rate in the 1st world is a fraction of what it used to be only 100 years ago. I have an older brother who is afflicted with allergies of all types and was a sickly baby. We joke with him that if he had been born in 1900 he would never have lived past 5 years old and that is probably the truth. In any case we have far more humans that would have died in childhood but who are alive and passing on their genes to other generations. I think the result is that we have "less strong" genes overall than we did just 100 years ago.
There's an alternate theory that allergies are the result of our environment being too clean. The trick that wisdom teaches us is to take all new pronouncements with a few grains of salt. Be particularly wary of the way statistical studies are presented. If, for example, a condition affects one person in a thousand, then a hundred percent increase will mean that two people in a thousand are affected. Most medical studies are more exaggerated than this example.