Chronic inflammation may explain why some mothers with obesity struggle with low milk production

A recent study published in The Journal of Nutrition has revealed that inflammation in lactating mothers who have obesity may interfere with the transfer of circulating fatty acids to the mammary gland, resulting in low milk production.

Obesity is associated with chronic inflammation and is a risk factor for insufficient milk production. Inflammation-mediated enzymes have been shown to suppress the uptake of fatty acids from the blood by body tissues, leading to high blood lipid concentrations. Fatty acids are critical for supporting milk production in the mammary gland, and therefore, inflammation could negatively impact milk production through this pathway. To test this hypothesis, a team of researchers led by Rachel Walker, a USDA-funded post-doctoral fellow, analysed blood, milk fatty acid profiles, and inflammatory markers from lactating women. The study included 23 women with very low milk production despite frequent breast emptying, 20 with moderate milk production, and 18 exclusively breastfeeding controls.

The researchers found that mothers with very low milk production had significantly higher obesity and inflammatory biomarkers, lower proportions of long chain fatty acids in milk, and a disrupted association between blood and milk fatty acids, compared to those with moderate milk production and exclusively breastfeeding controls. While milk and blood fatty acids were strongly correlated in controls, this was not the case in the very low or moderate milk production groups. These findings support the hypothesis that inflammation and obesity disrupt the transfer of fatty acids from circulation to the mammary gland, potentially contributing to insufficient milk production in women with obesity.

The study suggests the need for further investigation into the transfer of fatty acids to milk and its relationship with milk volume. The findings are of significant importance as it has been known for decades that mothers with obesity are at an increased risk of shortened breastfeeding duration. This study provides important new evidence that physiological differences, such as chronic inflammation, may contribute to some mothers’ struggles with milk production.