Eli5: Why are nut allergies and gluten intolerance so prevalent and serious in certain populations (like in much of the US), and negligible to the point of being even considered a myth in other parts of the world?

Question

Eli5: Why are nut allergies and gluten intolerance so prevalent and serious in certain populations (like in much of the US), and negligible to the point of being even considered a myth in other parts of the world?

In: Biology

Answer 1

All the added preservatives and chemicals added to western food would probably be the culprit here. Third world counties only eat homegrown food

Edit:

What on earth is this downvoted for? Correct me if I am wrong