Diet and premature birth influence the composition of breast milk

A new study from the Autonomous University of Madrid (UAM) reveals how maternal diet and premature birth can influence the composition of breast milk, specifically cytokines, important cellular communication molecules.

The work, published in the journal Antioxidants , highlights how these factors can affect the immune and gastrointestinal development of the newborn and highlights the need for adequate nutritional advice during breastfeeding, especially in mothers who have given birth prematurely or by cesarean section. .

The research, which explores for the first time the relationship between the Dietary Inflammatory Index (DII) and postpartum women's health, provides new insight into neonatal nutrition and its impact on long-term infant health.

Role of cytokines in breast milk

These molecules can be anti-inflammatory (IL-10 and IL-13), pro-inflammatory (IL8, TNFα) or chemokines, whose main function is the mobilization of inflammatory cells (MCP-1). They play a role in the immune and gastrointestinal development of the newborn and are crucial in inflammatory response processes.

Breast milk cytokines are particularly important in premature neonates (born before the 37th week of gestation) due to the immaturity of their physiological systems.

During lactation, cytokine levels in milk can vary depending on maternal factors, such as stress or diet, and neonatal factors, such as prematurity or illness.

Premature newborns present greater morbidities associated with inflammatory responses, due to the immaturity of their immune system. However, the factors that most influence breast milk cytokines are the subject of debate. Some studies show that prematurity increases concentrations of proinflammatory cytokines in milk. Others suggest that maternal diet may be more relevant.

Polyunsaturated fatty acids in the diet, such as omega-3 and 6 (n-3 and n-6), present in nuts and oily fish, can regulate inflammation. It has been shown that a maternal diet low in n-3 decreases anti-inflammatory cytokines in milk, but not all studies corroborate this relationship.

Influence of diet and premature birth

In the UAM study, the levels of cytokines in breast milk were examined, how they change during the first month of breastfeeding and the influence of prematurity and maternal diet.

Cytokines IL-10, IL-13, IL-8, TNFα and MCP-1 were analyzed in the milk of 51 women using electro-chemiluminescence with an MSD kit. Their diet was recorded and their nutritional profile was obtained, including energy, consumption of macronutrients, micronutrients, minerals and water. And all the variables were collected at two points: on days 7 and 28 of lactation.

The most relevant results showed that during the first month of breastfeeding, breast milk changes towards an anti-inflammatory cytokine profile. Among newborn factors, the presence of inflammatory morbidities and prematurity increased the levels of proinflammatory cytokines in milk.

However, a more detailed statistical analysis revealed that these neonatal factors do not directly influence this increase. Regarding maternal factors, women who decreased their Dietary Inflammatory Index (DII) during breastfeeding tended to improve the anti-inflammatory profile of their milk.

In short, the main factors that affect the cytokine content in breast milk are the breastfeeding period, prematurity and maternal diet. A premature or cesarean birth raises the levels of proinflammatory cytokines.

This study highlights the usefulness of maternal IID in determining the influence of diet on the inflammatory profile of milk. The results support the importance of nutritional counseling for women during breastfeeding, especially those who have had premature births or cesarean sections.

Image: Diagram of the presence of cytokines. Authors: David Ramiro and Silvia Arribas

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Bibliographic reference:

Ramiro-Cortijo, D.; Herranz Carrillo, G.; Singh, P.; Rebollo-Hernanz, M.; Rodríguez-Rodríguez, P.; Ruvira, S.; Martín-Trueba, M.; Martin, C.R.; Arribas, SM 2023 Maternal and Neonatal Factors Modulating Breast Milk Cytokines in the First Month of Lactation . Antioxidants , 12, 996. doi.org/10.3390/antiox12050996

Health Education Project for pregnant and lactating women: lifestyles and dietary patterns (PAC22-20/2ACT/22) financed by the Women's Institute of the Ministry of Equality (Spain).

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