Maternal dairy intake linked to lower concentrations of select human milk lipids

Maternal dietary patterns may influence the composition of human milk lipids, according to findings from a pilot study of 100 breastfeeding women. The research, presented at the Pediatric Academic Societies (PAS) 2026 Meeting, identified associations between maternal dairy intake and reduced concentrations of several lipid species in human milk.^1,2

The human milk lipidome comprises hundreds of lipid molecules that contribute to infant brain, gastrointestinal, and respiratory development. Although prior research has established that maternal diet can alter specific fatty acids, such as docosahexaenoic acid, less is known about how overall dietary patterns shape the broader lipid profile of human milk.

In this study, investigators evaluated 100 exclusively breastfeeding women and their healthy term infants at 1 month postpartum. Maternal dietary intake over the preceding month was assessed using a food frequency questionnaire, and dietary quality was quantified using the Healthy Eating Index 2015. Human milk samples were analyzed using a high-sensitivity lipid profiling platform, allowing for the measurement of 567 lipid species. Associations between dietary components and lipid concentrations were examined using linear regression with adjustment for multiple comparisons.

Among the 567 lipids analyzed, 64 were significantly associated with at least one dietary component. Oxidized triglyceride species, particularly OxTG (16:0/16:1/18:1(OH)), demonstrated the greatest number of associations, including negative relationships with total fat, polyunsaturated fat, and total sugar intake.

The most consistent findings were observed with maternal dairy intake. Of the 64 lipid species associated with dietary factors, 62 were linked to dairy intake, and all associations were negative. These included multiple triglycerides, diacylglycerols, and oxidized triglyceride species.

“Breastfeeding has numerous benefits for babies, including a lower risk of obesity, with breast milk being a dynamic fluid that may be influenced by a mother’s health and behaviors,” said Chang Lu, instructor of pediatrics at Boston Children's Hospital and presenting author of the study. “Lipidomics is an advanced technique that allows us to simultaneously survey over 500 lipids in human milk. Using this state-of-the-art approach, along with comprehensive assessments of maternal diet, our group found numerous relationships between a mother's diet and her breast milk lipid composition. Surprisingly, the strongest link was seen between maternal adherence to healthy dairy intake guidelines and lower levels of specific milk lipid species, including many triacylglycerols with omega-6 fatty acid chains. Interestingly, we found that higher dietary score for dairy intake was associated with lower levels of 7 oxidized triacylglycerols in milk. Limited data in adults suggest that oxidized derivatives of triacylglycerols in blood may be harmful for cardiovascular and metabolic health. It is not known yet what these findings mean for babies, which will be an important future direction for our group. Breast milk is the ideal form of nutrition for infants and this work has the potential to optimize the benefits of breastfeeding and inform personalized nutritional recommendations for breastfeeding mothers.”

The findings derive from the Mothers and Infants Linked for Healthy Growth study, a National Institutes of Health–funded observational cohort examining relationships between maternal factors and milk composition. Investigators across multiple institutions are evaluating how maternal nutrition, physical activity, and metabolic conditions influence milk constituents and infant outcomes.

The clinical implications of reduced concentrations of specific lipid species remain uncertain. Oxidized triglycerides have been associated in adult populations with adverse cardiometabolic outcomes, including atherosclerosis and glucose intolerance. However, the relevance of these findings in the context of human milk and infant health is not yet established.

The authors noted that further research is needed to determine whether these lipid changes have functional consequences for infants and whether dietary modifications during lactation could be used to optimize milk composition.

References

1. Pediatric Academic Societies. New study suggests maternal dairy intake consistent with recommendations is linked to lower levels of specific human milk lipids. Press release. April 24, 2026. Presented at the Pediatric Academic Societies (PAS) 2026 Meeting; Boston, MA.

2. Lu C, Dreyfuss JM, Uniyal A, et al. Maternal diet shapes the human milk lipidome. Presented at: Pediatric Academic Societies (PAS) 2026 Meeting; April 24-27, 2026; Boston, MA.