Impact of maternal nutrition on breast milk composition: a systematic review

Maternal nutrition have been suggested to have an impact on nutrients excreted in breast milk. Several studies have considered different aspects of maternal diet and various types of nutrients. In order to summarize and better define the available knowledge on the issue, we carried out a systematic review of the publications investigating the role of maternal diet on breast milk composition. We performed a Pubmed/Medline search of the papers published up to January 2015. We reviewed the manuscripts to identify the eligible studies according to predefined criteria. Studies were included if: (1) provided quantitative information on the relationship between maternal diet and any nutrient in breast milk; (2) were based on original observational or experimental studies; (3) included healthy term infants and healthy mothers. Exclusion criteria were: (1) investigating the role of supplements or probiotics; (2) considering the transfer of pollutants, toxic metals or contaminants from maternal diet to milk; (3) including marginally nourished populations; (4) including children and/or mothers with health problems. We identified 31 publications, including 1890 mother-child pairs. Twenty-four papers concerned observational cross-sectional studies investigating mothers’ usual dietary habits, while 7 papers described experimental (mainly cross-over) studies in which maternal diet was controlled and pre-determined. In 20 studies mature milk was collected 1 to 12 months postpartum, in 5 studies colostrum was collected a few hours/days postpartum, in 4 studies both colostrum and mature milk was collected, and in 2 studies mature milk was collected up to 24 months postpartum. The studies were quite different both in terms of characteristics of mothers’ diet considered and breast milk components examined. The majority of studies (17) focused on breast milk fatty acid composition, while the remaining investigated other milk components including protein (4 studies), total fats (4 studies), vitamins (5 studies), minerals (3 studies), and total energy intake (2 studies). Among the considered breast milk components, polyunsaturated fatty acids, monounsaturated fatty acids, saturated fatty acids, polyunsaturated/saturated fatty acids ratio, DHA acid, linoleic acid, linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, vitamin C, vitamin E, β-carotene, iron, and zinc were significantly influenced by maternal nutrition.