1. (No) health advantages of not breastfeeding – There are no health outcomes where not breastfeeding has been shown to be superior to breastfeeding (The one exception to this finding is among women with HIV. HIV can be passed along to babies thorough breast milk).

2. Health advantages of breastfeeding for babies – Breastfeeding offers significant protection against infection, such as gastro-intestinal infections, respiratory infections, ear infections. These immunological benefits tend to increase with the duration and exclusivity of breastfeeding. It is also known that these protective effects are limited to the period of actual breastfeeding (i.e, until the baby is weaned).

Breastfeeding also seems to offer advantages in terms of neuro-cognitive development. Specifically, breastfed children score a couple of points higher, on average, on IQ scales. However it is not currently clear whether this effect is due to something in the breast milk, something related to the act of breastfeeding, or something else pertaining to the characteristics/behaviors of these families.

3. Health advantages of breastfeeding for mothers – One advantage is that exclusive breastfeeding has a contraceptive effect. While perhaps not as important in developed countries, this is a very meaningful and significant health advantage for mothers in much of the developing world.

The second main finding is that breastfeeding offers protection against breast cancer. This protection seems to increase with the duration and number of children breastfed (i.e., the effect is cumulative).

Breastfeeding seems to have a small effect on weight loss (i.e., that breastfeeding mothers tend to lose their pregnancy weight slightly faster than mothers who do not breastfeed). It was stressed, however, that this effect is very slight. Therefore, we should take care not overstate this as a main health advantage of breastfeeding.

If, for whatever reason, six months of exclusive breastfeeding (with continued breastfeeding up to and beyond a year) is not going to work, an excellent option is to try to get to 3-4 months of exclusive breastfeeding (with continued “partial” breastfeeding after that to about a year). This amount of exclusivity and duration is likely provide 90-95% of the full effect of the health advantages of breastfeeding.