Former experimentation indicates that environmental factors do influence the composition of breast milk, and have a larger impact than previously believed. Because the composition of human milk is so unique and is affected by so many variables, many sources of error exist in the collection of data. However, it has been studied that certain nutrients and non-nutrient constituents of milk can decrease with a chronically lower maternal intake of these nutrients. This then can result negatively on the infant. Likewise, a chronically low intake of certain components can have a neutral result on the breast milk if the components are then sourced from the mother’s own internal reserves.
Maternal dietary intake can impact the proportions of different fatty acids present in milk samples. The intake of lipids affects milk composition by altering the type of fatty acid present. Lipid composition of milk demonstrates the unique way human milk components are sourced in the body. Fatty acids can be derived from plasma transported from the intestine/fat deposits or can be synthesized from glucose. Those synthesized within the mammary gland have a chain length of 16 carbons or less, whereas, the chain length of fatty acids derived from the maternal diet tend to be longer. During lactation, lipoprotein lipase activity in the mammary gland increases which hydrolyzes triglycerides, freeing the fatty acids for transport and further use within the cell.
Rather than the amount of fat intake by the mother affecting the amount of fat within the milk, we see that the type of fat consumed influences the fatty acid composition of the milk. An experiment in Great Britain compared the breast milk of four vegetarian women to that of four non-vegetarians. The results suggested that the milk from the vegetarian mothers contained five times as much C18:2 fatty acids within the early stages of lactation. As time progressed, however, the milk of both groups began to contain more fatty acids synthesized from the mammary gland. The type of diet of the mother seems to impact the type and source of the fatty acid used in the composition of breast milk. By using stable isotope methodology, the results of a study showing that diet composition affects milk fat synthesis were confirmed. The study further showed that when the mother’s energy levels are balanced, the “fatty acids derived directly from the diet account for approximately 30% of the fatty acid found in the milk.”
Moving forward, more research on factors that affect fatty acid content and how the type of fatty acid that is present due to environmental factor affects the human milk sample will be done. Also, the research can be compared to the group’s collected research in the lab. This research poses a challenge just because there are so many varying factors that can affect the composition of breast milk. Through this research so far, I have learned a lot about the complexity of human milk composition and the many bodily processes that contribute to its formation.