A new study published in The Journal of Nutrition suggests that inflammation in lactating mothers with obesity may disrupt the transfer of circulating fatty acids to the mammary gland, contributing to low milk production.
Obesity is associated with chronic inflammation and is a risk factor for insufficient milk production. Evidence suggests that suppression of inflammation-mediated enzymes inhibits uptake of fatty acids from the blood by body tissues, leading to high blood lipid concentrations. Fatty acids are critical to support milk production in the mammary gland, so inflammation could negatively impact milk production through this pathway. To test this hypothesis, USDA-funded post-doctoral fellow Rachel Walker, under the mentorship of co-senior authors Alison D Gernand and Laurie A Nommsen-Rivers (The Pennsylvania State University and University of Cincinnati, respectively) and colleagues analyzed blood, milk fatty acid profiles, and inflammatory markers from lactating women, including 23 with very low milk production despite frequent breast emptying, 20 with moderate milk production, and 18 from an exclusively breastfeeding control group.
Compared to those with moderate milk production and exclusively breastfeeding controls, mothers with very low milk production had significantly higher obesity, inflammatory biomarkers, lower proportions of long chain fatty acids in milk, and disrupted association between blood and milk fatty acids. Milk and blood fatty acids were strongly correlated in controls, but not in the very low or moderate milk production groups. These data support the hypothesis that inflammation and obesity disrupt mammary transfer of fatty acids from circulation to the mammary gland and may be contributing to insufficient milk production in women with obesity. These meaningful physiologic differences suggest the need to further examine fatty acid transfer to milk and the relation with milk volume. This is of high importance because we have known for decades that mothers with obesity are at increased risk of shortened breastfeeding duration. This study provides important new evidence that physiologic differences like chronic inflammation are contributors to some mothers’ struggles with milk production.
Walker RE, Harvatine KJ, Ross AC, Wagner EA, Riddle SW, Gernand AD, Nommsen-Rivers LA. Fatty Acid Transfer from Blood to Milk Is Disrupted in Mothers with Low Milk Production, Obesity, and Inflammation. The Journal of Nutrition, Volume 152, Issue 12, December 2022, Pages 2716-2726. https://doi.org/10.1093/jn/nxac220.
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