(AL01-01-25) Breast Milk Saturated Fatty Acids Are Directly Influenced by Dietary Intake: A Test of Beef Versus Coconut Oil-Based Substitute Beef

Objectives: To determine if a plant-based beef substitute has a distinct fatty acids profile compared to beef, and if these dietary differences affect breastmilk composition of fats and minor fatty acids, using samples from the Study of Nutrition in Postpartum and Early Life (SUPER) Feeding Trial.

Methods: Seventeen mother/infant dyads participated in SUPER, a 26-day double-blind, randomized crossover feeding trial comparing two diets: one with beef and one with a plant-based beef substitute. SUPER participants consumed a 6d whole food diet prepared with either beef or plant-based beef substitute, followed by a washout period and then the alternate diet. Breast milk samples (5 mL) were collected three times daily in provided Lansinoh food-safe, low-density polyethylene (LDPE) storage bags that were BPA, BPS, and phthalate-free. Upon receipt, samples were slowly thawed, divided into 1ml aliquots, and stored at -80°Celsius until analysis. Fatty acids from breast milk, beef, and beef substitute samples were converted to fatty acid methyl esters (FAME) and analyzed via gas chromatography with flame ionization detection (GC-FID), quantifying 27 fatty acids. Statistical analyses compared the levels of these 27 fatty acids between beef and beef substitute and in breast milk between the two diets.

Results: Significant variations were observed in 11 minor fatty acids (10:0, 12:0, 14:0, 14:1, 16:0, 16:1, 18:0, 18:3n-6, 20:0, 20:4n-6, and 22:5n-3) between breast milk samples collected during the beef and plant-based substitute diets (all p < .0001). These differences correlated directly with the fatty acid profiles of the experimental diets. For example, the high levels of refined coconut oil in the plant-based substitute led to increased proportions of 10:0, 12:0, and 14:0 fatty acids in breast milk.

Conclusions: Maternal diet has a direct and measurable effect on breast milk fatty acid composition. The elevated levels of saturated fatty acids associated with refined coconut oil in plant-based substitutes may pose unknown health risks for nursing infants. Further research is needed to explore the implications of maternal diet on infant health outcomes.

Funding Sources: Research coordinated by the National Cattleman’s Beef Association, a contractor to the Beef Checkoff.