It is because children need calcium and vitamin D.
I have actually read some interesting things about cows milk consumption in a book called 'the enzyme factor' by Hiromi Shinya.
He says that although milk has a large amount of calcium, it is not as easily absorbed as in other foods and can actually cause osteoperosis rather than prevent it. This is because when we have an injection of a high level of calcium, the concentration levels in our blood suddenly rises to abnormal levels. To combat this, the kidneys will secrete calcium through urine to restore the balance. This in turn means the calcium level will actually decrease. Over time this may lead to osteoperosis.
The theory is that foods with more slow release calcium are better because a slow absorbtion means a higher level will be retained.
Foods he suggests are small fish, shrimp and seaweed. I would say brocolli too.
cows milk is difficult to digest. the protein in it is 80% casein immediately clumps together when it enters the stomach. Homogenisation (making the milk one liquid rather than separating to milk and cream) puts air into the fat turning it into an oxidised fatty substance- can produce free radicals and have a negative effect on the body.
Pasturisation: at high temperatures 212 degrees. Enzymes are destroyed. he says he has heard that if you feed shop bought milk to a calf it will die within 4 to 5 days. He says life cannot be sustained with foods that do not contain enzymes.
that said, he explains that westernised peoples bodies have adapted to milk quite well over many years and can handle it better . People from countries such as Japan have a shorter history of drinking milk and have more issues to do with the effects.His children developed allergies like dermatitis when they were drinking milk, his wife was allergic to milk and developed Lupus (dont know whhat that is) but didnt know she was allergic and drank it while growing up at school. She died, but his childrens problems were cured when milk was eliminated from their diets.
This guy is the chief of surgical endoscopy at beth israel medical centre and clinical professor of surgery at albert einstein college of medicine. He has been studying peoples colons for 50 years,
BUT,
a lot of this is his own observations and conclusions, not medical fact.
he is possibly slightly a bit of a quack, but one with a lot of experience.
I still drink milk, not loads though.
My baby is 6 months and BF. When she gets to one year im sure i will be giving her milk, but i will also make sure she is getting the calcium and other nutrients she needs from other foods. If i see signs of allergies or other problems i may eliminate milk to see if it is the cause.