Selenium supplementation increases the polyunsaturated fatty acid content of human breast milk

Abstract

Although numerous dietary factors influence the fatty acid profile of human breast milk, little is known about the effect of trace minerals such as selenium. Consequently, the purpose of this study is to evaluate the influence of selenium supplementation during pregnancy and lactation on the concentration of breast milk fatty acids in healthy lactating women from New Zealand, an area of naturally low selenium status. Milk samples were obtained at parturition and 3 months postpartum from 22 women supplemented with either 50 μg selenium daily as selenomethionine or a placebo during pregnancy and lactation. Selenium concentration of breast milk was significantly increased by the supplementation (P = 0.0001 and 0.003, respectively), but glutathione peroxidase activity was unchanged. The selenium supplement also significantly increased the concentration of polyunsaturated fatty acids in breast milk (P = 0.02), especially linoleic acid (P = 0.02), and decreased the concentration of saturated fatty acids (P = 0.04). These data indicate that selenium plays a unique role in influencing the lipid content of human breast milk. J. Trace Elem. Exp. Med. 12:37–44, 1999. © 1999 Wiley-Liss, Inc.