Many teaching in medical schools today were raised in the better-living-though-chemistry age, when infant formula was thought to trump the attributes of breast milk. (Formula was certainly an improvement over the non-pasteurized cow's milk that killed many infants at the turn of the 20th century, when breast-feeding was not in vogue).

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Sure, we understand that all milk must be heat-treated or pasteurized to kill off harmful micro-organisms (in 1987 the FDA mandated pasteurization of all milk products for human consumption).

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Milk that is in its final package form for beverage use shall have been pasteurized or ultrapasteurized, and shall contain not less than 8.25% solids and not less than 3.25% milk fat .

FORBES: Why Milk Isn't As "Natural" As You Think