I think you are confusing intolerances and allergies.
about 90% of anaphylactic incidents in the UK are caused by nuts
Most the most common intolerance in the world is milk. And it isn't even really an intolerance, anymore than people are "intolerant" of eating sand.
Milk is not an adult food, it is a baby food, human babies can digest it, human adult can't. Except in two populations where a mutation has lead to the continuation of a baby enzyme into adulthood, some white northern Europeans, and the massia in Kenya/Tanzania
Therefore, 80% of the worlds adult population can't digest milk - and some white northern europeans class that as an "intolerance" when it is actually the human norm, and they are the deviants.
It could make people very ill, and even be dangerous, as could eating sand, but this is not a medical problem, this is the biological norm