A Comparison of Changes in the Fatty Acid Profile of Human Milk of Spanish Lactating Women during the First Month of Lactation Using Gas Chromatography-Mass Spectrometry. A Comparison with Infant Formulas

Breastfeeding is the ideal way to provide infants with the nutrients they need for healthy growth and development. Milk composition changes throughout lactation, and fat is one of the most variable nutrients in human milk. The aim of this study was to determine the main differences between the fatty acid (FA) profile of human milk samples (colostrum, transitional, and mature milk group) and infant formulas. Human milk samples were provided by lactating women from Granada. Moreover, different commercial infant formulas were analyzed. FAs were determined using gas chromatography coupled with mass spectrometry. According to the results, oleic acid was the predominant monounsaturated fatty acid (41.93% in human milk and 43.53% in infant formulas), while palmitic acid was the most representative saturated fatty acid (20.88% in human milk and 23.09% in infant formulas). Significant differences were found between human milk groups and infant formulas, mainly in long-chain polyunsaturated FAs (LC-PUFAs). The content of araquidonic acid (AA) and docoxahexaenoic acid (DHA) was higher in human milk (0.51% and 0.39%, respectively) than in infant formulas (0.31% and 0.22%, respectively). Linoleic acid (LA) percentage (15.31%) in infant formulas was similar to that found in human milk (14.6%). However, a-linolenic acid (ALA) values were also much higher in infant formulas than in human milk (1.64% and 0.42%, respectively).