GROW: The Book
So, a mutated gene is why humans drink milk beyond childhood.....
Lactase is still present in raw milk not just the intestines, making processing of the lactose still very possible.
"The lactase in raw milk, present from bacterial synthesis, appears to be inactivated by the pasteurization/homogenization processes." This is where the issue with lactose arises.
I found this article confusing. It supports raw milk yet goes sideways in many places.
I would question the mutated gene idea. No evidence is given. It is just stated as fact and we are expected to believe it.