Fatty Acid Composition of Breast Milk during Different Lactation Stages in China

Nearly 15 years of available evidence on the fatty acid composition of breast milk in China were summarized and the large amount of scattered research data with the data were collected in the survey. Finally,the national aggregate data of the composition of each provincial administrative region were obtained to analyze the differences of milk fatty acids in different lactation periods. A total of 4,727 cases of milk fatty acid from 17 provincial regions were included in the analysis,including 1327 cases of colostrum,900 cases of transition milk and 2500 cases of mature milk. The variation tendency of fatty acids with lactation and their causes were investigated. The results showed that with the prolongation of lactation period,the proportion of total SFA in breast milk was rising. The contents of C6:0,C15:0 and C18:0 were relatively stable and not affected by lactation period. In the SFAs affected by lactation period,except C20:0,C22:0 and C24:0,the content of other SFAs in colostrum was significantly lower than that in transition milk or mature milk(P<0.05). The proportion of total MUFA in breast milk showed a decreasing trend with the prolongation of lactation period,which decreased significantly during the transition milk period and then became stable. Only the content of C17:1 was not affected by lactation period. In the MUFAs affected by lactation period,except C16:1,the content of other MUFAs in the colostrum was significantly higher than that in the transition milk or mature milk(P<0.05). The proportion of total PUFA in breast milk increased first and then decreased with the prolongation of lactation period,and the changes of n-3 PUFA and n-6 PUFA were consistent with this trend. The results of analysis and comparison are beneficial for us to understand the composition of breast milk fatty acids and its changes with lactation period in China. It is hoped that this article can provide basic data for the study of the composition of breast milk fatty acids,related research on infant growth and development,and the development of infant formula.