Maternal Diet Quality and BMI as Predictors of Human Milk Composition and Exclusive Breastfeeding Duration

BackgroundPoor diet quality and high body mass index (BMI) contribute to inflammation, which may influence human milk composition and exclusive breastfeeding (EBF) duration. ObjectiveWe evaluated maternal diet and prepregnancy BMI as predictors of human milk C-reactive protein (CRP) and long chain fatty acid concentrations (%LCFA), and EBF duration. MethodsWe utilized the Global Exploration of Human Milk Study-Cincinnati subset (n=114), where healthy dyads continued follow-up if [&ge;]75% of feeds were breastmilk at 4 weeks postpartum. We computed a Dietary Inflammatory Index (DII) from diet recalls obtained between 4-13 weeks postpartum, where higher score indicates a more proinflammatory diet. Milk CRP and fatty acid analyses were performed on week 4 milk. We compared milk CRP across 4 combinations of DIIxBMI using the Kruskal Wallis test, with BMI categorized as normal versus elevated (<25 versus >25 kg/m2), and DII split at the median. Linear regression was used to examine DII and BMI as predictors of %LCFA. Logistic regression was used to examine DII tertiles and BMI as predictors of EBF duration. ResultsMilk CRP concentrations differed across DIIxBMI groups (p=0.009): the low DII/normal BMI group had the lowest milk CRP (n=30, median [Q1, Q3], 64.3 [38.2, 121.4] ng/mL) versus all other groups (n=70, 124.1 [71.2, 181] ng/mL, p=0.022). Lower milk %LCFA was predicted by higher DII score ({beta}{+/-}SE = -0.68 {+/-} 0.21, p=0.002, n=103) and higher BMI ({beta}{+/-}SE = -0.13 {+/-} 0.01, p=0.043, n=114). Having the highest DII tertile and elevated BMI lowered the odds of EBF at week 6 (OR [95% CI]: 0.26 [0.07, 0.85]) compared to the referent group (low or medium DII, normal BMI). ConclusionsMilk CRP concentrations were lowest in women with a more anti-inflammatory diet and normal BMI. Both higher BMI and proinflammatory diet predict lower milk %LCFA and lower EBF prevalence at week 6.