once upon a time virtually no human beings drink any kind of milk. Then they learned how to domesticate animals and people started drinking animal milk. This was a radical new dietary introduction. Now we consider it perfectly normal
Once upon a time no Europeans ate any kind of potatoes, yams, peppers, strawberries, blueberriesetc. why? Because those are New World foods and they had not discovered the New World yet. Now Europeans and people of European descent thrive on those foods
Cinnamon and oranges both come from the east.
Just because a specific population has not beaten a certain type of food, doesn't mean that it's wrong or toxic for them to be introduced to that food