Background: Dietary long-chain polyunsaturated fatty acids are known to benefit infant development. After birth, human milk provides arachidonic, eicosapentaenoic, and docosahexaenoic acids to the infant. Endocannabinoids are endogenous lipid mediators derived from the long-chain polyunsaturated fatty acids. Although the roles and the mechanisms of action are not fully understood, previous researchers have suggested that endocannabinoids might play a role in infant feeding behavior.
Research aims: To assess (i) maternal dietary intake of long-chain polyunsaturated fatty acids and (ii) their relationship to concentrations of fatty acids and derived endocannabinoids in human milk.
Methods: For this exploratory-longitudinal study, participants (N = 24) provided dietary intake data and milk samples. Fatty acids and derived endocannabinoids: Arachidonylethanolamide, arachidonoylglycerol, docosahexaenoyl glycerol, eicosapentaenoyl ethanolamide, and eicosapenaenoyl glycerol were identified in their milk by liquid chromatography-mass spectrometry and correlations to dietary fatty acids were assessed.
Results: Participants were not consuming recommended amounts of docosahexaenoic acid. Significant correlations (p ≤ .05) were only found between dietary docosahexaenoic and eicosapentaenoic acids and the concentrations of these in human milk. Moreover, only dietary docosahexaenoic acid was correlated (p = .031) with its corresponding endocannabinoid, docosahexaenoyl glycerol.
Conclusions: To the best of our knowledge, this may be one of the first studies evaluating relationships between dietary long-chain polyunsaturated fatty acids and multiple endocannabinoids in human milk. Our findings suggest that endocannabinoid concentrations could be modulated by dietary precursors. Future research studies can be designed based on these data to better elucidate the roles of endocannabinoids in human milk for infant health and development.
Keywords: breastfeeding; human milk; infant nutrition; maternal nutrition; milk composition.