Since the maternal decision to breastfeed is associated with numerous health-related factors, it is difficult to draw firm conclusions on the causality between breastfeeding and health benefits. Nevertheless, it is estimated that ∼1.5 million deaths could be prevented by increased levels of breastfeeding. In industrialised countries, breastfeeding is associated with a demonstrable impact on infant morbidity but not on infant mortality.

Collectively, the available data indicate an association of breastfeeding with a reduced risk of infectious diarrhoea and acute otitis media and a possible protection against respiratory infections.

Although there are indications for effects on later blood pressure (BP) (mean difference for systolic BP −1.21 mm Hg (95% CI −1.72 to −0.70) and for diastolic BP −0.49 mm Hg (95% CI −0.87 to −0.11) and on total cholesterolaemia (mean difference −0.18 mmol/l (95% CI 0.06 to 0.30 mmol/l)), there is no evidence that breastfeeding has an effect on cardiovascular morbidity and mortality. Breastfeeding has the potential to contribute to a reduction of later obesity development in childhood and adolescence (∼20–25%).

A protective effect of breastfeeding on the occurrence of diabetes type 1 later in life remains controversial. Breastfeeding may protect against coeliac disease but may only delay the onset of symptoms. The evidence for a protection of breastfeeding against malignant disease is weak.

Breastfeeding may be associated with a small advantage in cognitive development (∼+3–5 points) persisting into adulthood, which may not be of major importance for an individual but could provide a significant advantage on a population basis.