Determinants of energy, protein, lipid, and lactose concentrations in human milk during the first 12 mo of lactation: the DARLING Study

Abstract

Factors associated with concentrations of energy-yielding nutrients in human milk were examined at 3, 6, 9, and 12 mo postpartum in the DARLING (Davis Area Research on Lactation, Infant Nutrition and Growth) Study. Samples were obtained by complete expression of alternate breasts over 24 h. Milk energy density was highly correlated with lipid concentration; both were positively related to maternal percent of ideal body weight (%IBW) at 6, 9, and 12 mo and negatively related to milk volume at 3 mo and to parity at 12 mo. Milk protein concentration was negatively related to milk volume at 6 and 9 mo and positively related to nursing frequency at 6 mo and %IBW at 9 mo. Milk lactose concentration was positively related to milk volume at 6 and 9 mo and to continued amenorrhea at 9 mo. In a subsample who completed dietary records, protein intake was positively associated with lipid concentration after 16 wk postpartum but not before. These findings suggest that milk composition is more sensitive to maternal factors such as body composition, diet, and parity during later lactation than during the first few months.

Breast milk composition and infant nutrient intakes during the first 12 months of life

“…energy, protein, NPN, lactose and fat content, are consistent with previous observations [22][23][24][25] . There was a great variability in the composition between mothers and during lactation.…”

Field and laboratory methods in human milk research

“…However, prior research has shown extensive variation in maternal behaviors that determine infant access to milk (Gray, 1995;Vitzthum, 1994). Jenness, 1979;Mandel et al, 2005;Michaelson et al, 1994;Nommsen et al, 1991 Water (86.0-88.0 g) Ogra et al, 2006;Vaughan et al, 1979 Fat (2.5-6.0 g) Brown et al, 1986;Mitoulas et al, 2002;Nommsen et al, 1991;Prentice et al, 1981a;WHO, 1985 Myristic acid (14:0) Palmitic acid (16:0) Linoleic acid (18:2n-6) Alpha-linolenic acid (18:3n-3) Arachidonic acid (20:4n-6) Docosahexaenoic acid (22:6n-3) Protein (0.83-1.30 g) Brown et al, 1986;Mitoulas et al, 2002;Nommsen et al, 1991;Prentice et al, 1981a;WHO, 1985 In addition to inter-individual variation, there is considerable variation in milk production within an individual woman, and even within a single feed (Daly et al, 1993a;Kent et al, 2006). Foremilk, the first milk expressed during a feeding, is usually relatively dilute and low in fat compared with hindmilk (Daly et al, 1993a), the last milk consumed during in a feeding bout.…”

High levels of DDT in breast milk: Intake, risk, lactation duration, and involvement of gender

“…Since milk fat makes up a significant proportion of the energy component of breast milk (Nommsen et al, 1991), and organochlorine pesticides associate with the triglycerides in the fat globules of the milk (Hugunin and Bradley, 1971), we hypothesised that DDT levels in milk of mothers breastfeeding baby boys might also be greater. However, sugars and protein also contribute towards energy content and the statistical analyses can therefore only be done on whole milk.…”