Determination of Seasonal Fluctuations of Fat In Donated Human Milk

Abstract

Although there are many environmental factors that can alter the lipid content of human or bovine milk, the majority of the limited available research shows that fat composition is typically higher in milk produced during the warmer months of the year and lower in the cooler ones. The primary objective of this research was to identify the relationship between fat content in human milk and average or high monthly temperature. Analysis revealed a significant positive correlation between fat content with both average temperature (r = +0.08, p less than or equal to 0.01) and high temperature (r = +0.07, p = 0.05). The data were then filtered and the same statistical tests were run to include only those samples with a fat content of 2.4-4.0 g/dL (N=536). This is the typical range reported in the milk banking industry.Analysis of the filtered data revealed protein content was significantly negatively correlated with both average temperature (r=-0.11, p less than or equal to 0.05) and high temperature (r=-0.11, p less than or equal to 0.01). The wide range of fat content in the original sample indicates that the samples tested included substantial amounts of hindmilk or foremilk that were either higher in fat or lower in fat, respectively. Results reveal that macronutrient content of either fat or protein may change depending on temperature and perhaps point of expression.