Search for: All records

Abstract ObjectivesThis study explored differing levels of macronutrients in breast milk in relation to maternal anemia and hemoglobin. MethodsArchived milk specimens and data from a cross‐sectional sample of 208 breastfeeding mothers in northern Kenya, originally collected in 2006, were analyzed; data included milk fat, maternal hemoglobin concentration, and anemia status (anemia defined as hemoglobin <12 g/dL). Total protein and lactose were measured and energy was calculated. To explore the association between milk outcomes (fat, protein, lactose, and energy) and anemia, regression models were constructed with and without adjustment for maternal age, parity, and time (days) postpartum. The same models were constructed using hemoglobin as a continuous predictor in lieu of dichotomous anemia to explore the role of hemoglobin levels and anemia severity in predicting milk outcomes. ResultsThe group comparison indicated significantly higher milk protein and lower milk fat for anemic mothers relative to nonanemic counterparts. After adjustment for maternal age, parity, and time postpartum, maternal anemia was associated with significantly higher milk protein (P = 0.001) and significantly lower milk fat (P = 0.025). Hemoglobin had a significant inverse relationship with milk protein (P = 0.017) and a marginally significant positive relationship with milk fat (P = 0.060) after adjusting for the maternal variables. Neither anemia nor hemoglobin was significant in predicting lactose or milk energy. ConclusionsMaternal anemia and hemoglobin concentration may be associated with complex changes in milk macronutrients. Future research should clarify the impact of maternal anemia on a range of breast milk components while accounting for other maternal characteristics. 

Abstract BackgroundMaternal anemia has adverse consequences for the mother‐infant dyad. To evaluate whether and how milk nutrient content may change in ways that could “buffer” infants against the conditions underlying maternal anemia, this study assessed associations between milk macronutrients and maternal iron‐deficiency anemia (IDA), non‐iron‐deficiency anemia (NIDA), and inflammation. MethodsA secondary analysis of cross‐sectional data and milk from northern Kenya was conducted (n = 204). The combination of hemoglobin and transferrin receptor defined IDA/NIDA. Elevated serum C‐reactive protein defined acute inflammation. The effects of IDA, NIDA, and inflammation on milk macronutrients were evaluated in regression models. ResultsIDA (β = 0.077,p =.022) and NIDA (β = 0.083,p =.100) predicted higher total protein (ln). IDA (β = −0.293,p =.002), NIDA (β = −0.313,p =.047), and inflammation (β = −0.269,p =.007) each predicted lower fat (ln); however, anemia accompanying inflammation predictedhigherfat (β = 0.655,p =.007 for IDA and β = 0.468,p =.092 for NIDA). NIDA predicted higher lactose (β = 1.020,p =.003). ConclusionsMilk macronutrient content both increases and decreases in the presence of maternal anemia and inflammation, suggesting a more complicated and dynamic change than simple impairment of nutrient delivery during maternal stress. Maternal fat delivery to milk may be impaired under anemia. Mothers may buffer infant nutrition against adverse conditions or poor maternal health by elevating milk protein (mothers with IDA/NIDA), lactose (mothers with NIDA), or fat (mothers with anemiaandinflammation). This study demonstrates the foundational importance of maternal micronutrient health and inflammation or infection for advancing the ecological understanding of human milk nutrient variation. 

Objective: Folate in breastmilk has important implications for offspring health and survival given the essential role of this vitamin in DNA synthesis, epigenetic functions, and amino acid metabolism. Yet, little is understood about the variation of folate in breastmilk and transfer across the postpartum year and beyond. Published studies tend to be limited to milk during days/weeks postpartum, and none applied an evolutionary perspective of parental investment. Methods: A secondary analysis of the data and specimens from 200 breastfeeding mothers within 1.5 years postpartum in food-insecure northern Kenya was conducted. ELISA determined folate-binding protein (FOLR1) in cryogenically archived breastmilk and maternal blood specimens, originally collected in 2006. Maternal folate was defined as blood serum FOLR1 multiplied by –1 because elevated FOLR1 is associated with folate deficiency. The concentration of milk FOLR1 was evaluated in relation to maternal folate and 1) infant sex (Trivers-Willard hypothesis), 2) time postpartum and parity (maternal residual reproductive value) using regression models adjusted for covariates. Results indicated: 1) no Trivers-Willard effect; 2) support for time postpartum but not for parity. Maternal folate and time postpartum inversely predicted milk FOLR1. There was an interaction between these variables (p<0.05). Maternal folate improved over time at a varying rate while milk FOLR1 decreased at a relatively steady rate. This inverse relationship became stronger as time advanced. Conclusion: The priority shift from the investment in current offspring toward maternal soma and potential future offspring in this study provides empirical support for the evolutionary hypothesis of parental investment and parent-offspring conflict. This study was funded by NSF (BCS #1638167), and the Wenner-Gren Foundation (Grant #9278). The original data/specimen collection was supported by NSF (BCS #0622358) and the Wenner-Gren Foundation (Grant #7460).