Human milk is still best

Editor—Over 10 years ago Barker et al postulated the hypothesis of fetal programming by showing that low birthweight babies had a higher mortality from ischaemic heart disease.¹ Subsequently, fast postnatal catch-up growth was found to be an additional risk factor for ischaemic heart disease,² showing that early childhood programming was as important as the milieu in the womb. The most important form of early childhood programming and the form most amenable to beneficial intervention is nutrition—particularly breast feeding, or the lack of it.

Forsyth et al studied long chain fatty acid supplementation in infant formula and later blood pressure in childhood, and their findings will no doubt greatly influence the strategies of infant formula companies for years to come.³ However, the key finding should be that breast feeding does it all naturally, and for free. Sufficient evidence suggests that human milk, besides its role in preventing acute childhood infections, also protects against chronic diseases in childhood and beyond. The first commercially sold milk food for infants was formulated 136 years ago, yet the search for an ideal formula still continues.

Two years ago an article published in the BMJ raised considerable consternation when it implied that extending the duration of breast feeding beyond 3 months decreased brachial arterial distensibility in young adults and hence increased their theoretical risk of developing hypertension later.⁴ To support their findings, the authors quoted another paper from Barker's group, which found that men who were breast fed and not weaned at 1 year old had a higher chance of death from ischaemic heart disease compared with those breast fed for less than a year.⁵ What was not emphasised was that the same was true for purely bottle fed men. Human milk is the ultimate form of early nutrition for children, and the search for the ideal substitution infant formula will never be concluded satisfactorily.