Human milk lipids: an overview

It is estimated that well-nourished women secrete over 6 kg of fat into milk during a 6-month period of breastfeeding, which makes the lactating breast one of the most lipogenic organs in the human body. In addition to being a primary source of energy for neonates, milk lipids participate in the delivery of micronutrients, including fat-soluble vitamins and essential fatty acids required for infant development. The lipid content of human milk averages 3.4% w/v, which is about the same as that of major dairy species, such as cattle and goats, but significantly less than the approximately 50% found in aquatic mammals. The precise composition of lipids in the milk of humans and other mammals is variable and influenced by diet, genetics, and lactation stage, among other factors. Improvements in bioanalytical methods for lipids and proteins have led to a greater and more detailed understanding of the composition and complexity of human breast milk lipids and their role in neonatal nutrition and human health.