The thinking goes like this (spot the flaws):
- Not all human beings have the enzymes to digest unprocessed milk.
- In fact in some races and cultures milk is not drunk in its raw state.
- This means that for those races milk is not a good food. It makes them ill.
- Ergo, milk is not a good or natural food for human beings.
- Therefore all of us should stop using it as a source of nourishment.
There's another bit of the argument which appeals to "nature", and I'll have more to say about that later, because it's another very bad argument, but this one should be kept separate from the one given above.
As any rational being can see, the fact that some people don't have the enzymes to digest lactose does not mean that lactose is damaging to those who do have the necessary digestive juices. On the contrary, if you do have them, milk is a source of nourishment.
Also, it is well known that the races that do generally have the ability to digest milk are the ones who live in places where milk is a crucial part of the diet. For instance in northern climes and in areas of mountain pasture, you cannot grow high protein cereal crops. Humans can't digest grass but cows can. Cows are grazed on the grass and they produce a high energy and high protein yield, namely milk, that enables human beings to survive in those parts of the world, and to secure an adequate intake of vitamin D, calcium and protein. This is essential not just to growing children but to adults and elderly people, to prevent rickets and osteoporosis as well as general malnutrition. So it's not surprising that the lactose enzymes were a survival factor in those populations who live in such climates and in places where pasture is the only way to secure a viable diet. This means it's not just normal but vital for people in this part of the world to use milk and milk products as a staple part of a healthy diet from local resources.
Here is a picture of a child with rickets. Go to the location by clicking on the image and there's information there about how rickets is connected to lack of milk in people in northern climes and people with dark skins or those who can't digest milk. It was to prevent this happening that free codliver oil and free school milk was introduced with the welfare state in this country. It's made rickets a thing of the past, but if people start campaigning against drinking milk on specious grounds such as the above we'll have a very sad and unhealthy nation again. Does Richard take cod liver oil? I doubt it. Take care, old thing! Brittle bone disease on its way...
is some more information about the discovery of the importance of vitamin D, and other things you might not know that it helps with.