Breast milk is most commonly known for its passive protection against infections and possible prolonged health benefits for newborns. A new lead study revealed that fatty acid (FA) levels in breast milk were highly correlated with maternal dietary fat intake in a South Korean female population.
Breast milk is a primary biologic source of nutrition for newborns and infants as it has bioactive components that not only provide protection against pathogen infection and inflammation but also contributes to other health benefits (immune maturation, organ development, and healthy microbial colonization). Fat and fatty acids (FAs) present in breast milk acts as a potential source of energy and play a key role in the growth of infants. The composition of human milk is influenced by some factors related to dietary intake, pregnancy time, and lactation. Therefore, maternal diet consumption acts an important contributing factor for determining the variation in composition of polyunsaturated fatty acids (PUFA) in milk. Even though FAs like linoleic acid (LA) and α-linolenic acid (ALA) are not present in the mother or the newborn, they can still be obtained from the dietary intake of long-chain PUFA (LCPUFA); however, limitations exist as infants cannot synthesize sufficient amounts of FAs from precursors. Thus, it is extremely important to provide adequate FAs in the diet from early infancy. Therefore, Hyesook and his team at Ewha Womans University, Republic of Korea, have investigated the association of breast milk fat content and composition with dietary intake in a population of South Korean mothers; the interesting results were published in the British Journal of Nutrition, 2017.
A total of 238 healthy breastfeeding mothers from the Human Milk Micronutrients Analysis Research were recruited as study subjects. Researchers evaluated the fat content from the milk samples by collecting dietary intake data for 3 consecutive days using a food record. After the breast milk sampling, the macronutrient concentrations of fat, lactose and protein levels were estimated using MilkoScan FT2 (Foss Analytical) while FA analysis was carried out using GC flame ionization (GC-FID) detector. The results of the study revealed that most of the breastfeeding women were an average age of 31.6 years with BMI of 22 kg/m2. The average fat content was observed to be 3.31g in 100ml of breast milk. The concentrations of various forms of fatty acid in breast milk varied. In addition, the link between maternal diet and fat content and FA composition of breast milk was adjusted for potential confounding factors such as maternal age, BMI, supplement use and infant age. Therefore, dietary intakes of various forms of FA were positively correlated with the corresponding FA in the milk samples. FA levels in breast milk and maternal diet are highly correlated.
In short, positive correlation exists between FA content of breast milk and dietary intake in lactating mothers of South Korea, indicating higher levels of FAs and total PUFAs. Availability of information on maternal plasma or erythrocyte (red blood cell) FA content, genotyping of desaturase enzyme (which helps animals synthesize PUFAs) and study of a generalized population would potentially improve the reliability of the study results. In addition, studies are warranted to explore factors that may be associated with changes in FA composition in human milk.
Written By: Manche Santoshi, PhD