Human Milk: Composition, Clinical Benefits and Future Opportunities. Группа авторов

in verbal IQ at 6.5 years [30].

      These two pieces of experimental evidence give weight to the view that studies that show an association between breastfeeding and superior cognitive outcome are causal.

      Cardiovascular Risk Factors

Many epidemiological studies link breastfeeding to CVD risk factors. In our large historic RCT of EHM versus CM exposure in preterm neonates, we found at the 16-year follow-up that the EHM group had favorably reduced the LDL:HDL cholesterol ratio, diastolic blood pressure, insulin resistance, and metabolic tendency to fatness (leptin resistance) [31–33]. Thus, early HM feeding in a strictly randomized trial reduced 4 key risk factors for CVD. The effect size was large; for instance, the impact of early HM feeding on later cholesterol alone would be expected in adults to reduce CVD by 25% and death by 13–14%. These data add weight to the causal nature of a protective role of breastfeeding for future obesity and CVD.

      Atopic Disease

The relationship between breastfeeding and later atopy has been observational and uncertain. In our historic RCT comparing EHM with CM exposure, those with a family history of atopy fed an EHM diet had a major reduction in eczema, food and drug reactions, and wheezing at the 18-month follow-up [34]. Thus, strict experimental evidence confirms that HM, at least in those with a family history of atopy, is protective against future development of atopic phenomena.

      Conclusion

      Clearly, the HM-fed preterm infant is not a perfect model for the breastfed term infant, and some outcomes considered above would not occur in term infants. Nevertheless, it is a very useful model and conceptually, experimental studies in preterm infants add much weight to the view that breast milk is likely to have broad and important causal effects on short- and long-term outcomes in healthy full-term infants.

      Further Models

      Given the difficulty in providing an evidence-based underpinning for the impact of breastfeeding on clinical outcome, it is important to explore creatively further opportunities for experimental studies. In this paper, I have considered the value of RCTs in preterm infants and noted the inventive Belarus study on breast milk and cognitive development in term infants. One potentially promising area is the use of RCTs to study the impact on outcome of individual components of breast milk, for instance, HM oligosaccharides.

      Overview

      It has been an objective in this paper to examine some of the general principles that underlie the science of breastfeeding medicine in order to help strengthen this important field, in the interests of improving infant, child, and population health. The critique in the 3 sections of this paper – on human evolution, HM as a gold standard, and the proposed benefits of breastfeeding has significant, practical clinical and public health implications. Breastfeeding and indeed the use of HM in neonatal intensive care is entering a new era of quite unexpected importance for human biology and health.

      Disclosure Statement

      Alan Lucas has taken part in educational events organized by infant food, breast milk and feeding device companies for which he has received an honorarium and expenses. He has provided medical scientific advice to breast milk companies for which he has received consultancy payment.

      References

1Dugdale AE: Evolution and infant feeding. Lancet 1986;i: 670–673.

2Cordain L, Eaton B, Sebastian A, et al: Origins and evolution of the Western diet: health implications for the 21st century. American Society for Clinical Nutrition. Am J Clin Nutr 2005; 81: 341–354.

3Fomon SJ: Nutrition of Normal Infants. St. Louis, Mosby, 1993, p 3.

4Zimmerman DR, Speer VC, Hays WV: Injectable iron dextran and several oral iron treatments for the previous iron deficiency of baby pigs. J Anim Sci 1959; 18: 1409–1415.

5Hallberg L: Discussion of Cook JD and Bothwell TH: Availability of iron from infant foods; in Stekel A (ed): Iron Deficiency in Infancy and Childhood. New York, Raven, 1984, p 144.

6Simopoulos AP: The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother 2002; 56: 365–379.

7Hoobler I, Sloan RE, National Research Council (US) Food and Nutrition Board: The Composition of Milks: A Compilation of the Comparative Composition and Properties of Human, Cow and Goat Milk, Colostrum and Transitional Milk Washington, National Academy of Sciences, 1953.

8Department of Health and Social Security of Great Britain: The Composition of Mature Human Milk. London, Her Majesty’s Stationery Office, 1977.

9Lucas A, Gibbs JH, Baum JD: What’s in breast milk? Lancet 1977; 309: 1011–1012.

10Lucas A, Lucas PJ, Baum JD: Pattern of milk flow in breast-fed infants. Lancet 1979;ii: 57–58.

11Lucas A, Lucas PJ, Baum JD: The nipple-shield sampling system: a device for measuring the dietary intake of breast-fed infants Early Hum Dev 1980; 4: 365–372.

12Lucas A, Ewing E, Roberts SB, Coward WA: How much energy does the breast fed infant consume and expend? BMJ 1987; 295: 75–77.

13Kirk PL: Kjeldahl method for total nitrogen. Anal Chem 1950; 22: 354–358.

14Donovan SM, Lönnerdal B: Isolation of the nonprotein nitrogen fraction from human milk by gel-filtration chromatography and its separation by fast protein liquid chromatography. Am J Clin Nutr 1989; 50: 53–57.

15Singhal A, Lucas A: Early origins of cardiovascular disease: is there a unifying hypothesis? Lancet 2004; 363: 1642–1645.

16Der G, Batty GD, Deary IJ: Effect of breast feeding on intelligence in children: prospective study, sibling pairs analysis, and meta-analysis. BMJ 2006; 333: 945.

17Schandler RJ, Abrams SA, Hoppins AG: Infant benefits of breastfeeding. UpToDate. https://www.uptodate.com/contents/infant-benefits-of-breastfeeding.