You quoted me as saying I assume you do. Do we actually know that paleolithic hunter-gatherers were lactose-intolerant? As I understand it, the individual body loses the ability to digest lactose if it doesn't use that ability. Is there reason to think that the intolerance is inherited/evolved?
My point about agriculture is that many agricultural products, especially grains, require processing - i.e. pre-digesting - before we can eat them in any quantity. That interference with the natural digestive process is the cause of a lot of our nutritional problems.
We invented agriculture to make available more food (fuel) of kinds that are not easily digestible. To make them digestible, we have to process many of the nutrients out of them. I maintain that we'd be better off eating roots, berries and grubs - but there wouldn't be very many of us.
Okay - sorry if I misunderstood.
As for lactose-tolerance, I'd always just assumed it was genetically based. Societies with milk and cheese had higher levels of lactose-tolerance because of past natural selection - but I suppose it's equally well explained if people who grow up with milk and cheese in their diet retain the ability to digest it.
A very cursory glance through Google suggests there is a genetic basis - see
here from the American Journal of Human Genetics, for example. I don't know how well supported the idea is, though.