Throughout history, milk has commonly been regarded as a vital part of a balanced diet. When a baby is born, breast milk is the best form of nutrition; this no one can disagree with (Read here on black market breast milk). All mammals nurse their young, and breast milk is so beneficial in many ways for a newborn. After a year or so, this is usually substituted by cow’s milk or milk from other animals. Humans are the only species who continue to drink milk after being weaned.