Abstract:

Objective: To analyze the levels of arachidonic acid(AA) and docosahexaenoic acid (DHA) in the breast milk of lactating mothers in Changchun City of Jilin Province, and to explore their influence factors.Methods: The lactating mother's basic information was collected with questionnaire, and the breast milk of lactating mothers on postpartum 22-25 d was obtained and the 3-day 24-hour dietary recall method was used to investigate the dietary intake information of 514 healthy lactating mothers.The Food Composition Table of China 2009 was used to calculate the intakes of five kinds of polyunsaturated fatty acids (PUFAs)in diet of lactating mothers and the gold key nutrition expert system software for corresponding nutrient analysis was used to calculate the amount of various kinds of foods in the lactating mothers' daily diet.The levels of AA and DHA in breast milk were determined with gas chromatography and the linear regression was used to analyze the related factors of AA and DHA levels in breast milk.Results: ①The average concentration of AA in breast milk of 514 lactating mothers was (0.08±0.04)g·100 g^-1, and the average concentration of DHA was(0.05±0.04)g·100 g^-1.②The single factor correlation analysis results showed that the oil intake was both positively correlated with AA and DHA levels in milk of lactating mothers(r=0.360, r=0.354, P<0.001), while the intakes of linoleic acid(LA), alpha linolenic acid(ALA), eicosapentaenoic acid(EPA), DHA, dairy and meats and seafood in diet were both negatively correlated with AA (r=-0.321, r=-0.280, r=-0.255, r=-0.299, r=-0.196, r=-0.306, P<0.05)and DHA(r=-0.315, r=-0.279, r=-0.175, r=-0.189, r=-0.248, r=-0.142, P<0.05).③The linear regression analysis results showed regression equation that dairy intake(β=-0.265) and EPA intake(β=-0.144) were both negatively correlated with the level of AA(P=0.009), and dairy intake was also negatively correlated with the level of DHA(β=-0.233, P<0.001).Conclusion: The AA and DHA levels in breast milk of lactating mothers didn't increase with the increasing of intake of milk or dairy products in the study.Moreover there is a competitive relationship between n-6 and n-3 series polyunsaturated fatty acids in the process of metabolism.

Key words: lactating mothers, breast milk, arachidonic acid, docosahexaenoic acid