One reason may be the evidence supporting better brain development in breast-fed infants.
Breast milk contains infection-fighting antibodies that pass from mother to child.
I think it really helps with immunities and possibly with allergies. About 20 different studies suggest they are 3 to 5 IQ points smarter than formula-fed babies. The compounds in breast milk, long chain polyunsaturated fatty acids with names such as DHA and AA , may actually speed up brain development. Essential fatty acids are necessary for the normal development of cells in our body, including neurons or brain cells, explained pediatrician Dr. Elizabeth Dickey. Moms have to learn it.