Besides the obvious interest of the breast-feeding in the establishment of relation mother-child, the feeding in the breast protects the child, not only against the gastro-intestinal and respiratory infections (otites), but also against m ning es infections. Studies also showed that the rate of decease by cot death was weaker at the children's nursed in the breast. The breast-feeding could also protect, in the long term, against some auto-immune affections such as c liaque illness, illness of Crohn or diabetes insulinod pendant; allergies, asthma and eczema seem also less frequent at the children having been breast-fed.

But the breast-feeding is also interesting for the mother. Hormones of lactation would protect against the cancers of ovary and of breast, and lactation would also have a protective effect of the anaemia of the post - partum and of the baby blues. Moreover, studies showed that the fractures of the neck of the femur are less frequent at the women's who nursed that to others; this surprising effect would be linked to a revitalisation of the phosphocalcique metabolism. Finally, the exclusive feeding round the clock is a means of relatively efficient contraception (98 %), during first six months and in the absence of return of layers (a contraception by progestative pure pill is however possible and recommends, because progestatifs passes only not much or not in the milk and do not interfere).