UC Santa Barbara researchers have discovered that the immune status of postpartum mothers changes depending on how they feed their baby. In a study published in the journal Scientific Reports, researchers found that certain inflammatory proteins peak at different times of day, depending on whether the mothers breastfeed, pump, or formula-feed their babies.ain inflammatory proteins, or substances secreted as part of an immune response, peak at different times of day and correlate with whether mothers breastfeed, pump, or formula-feed their babies. Amy Boddy, a human biologist and evolutionary theorist at UCSB’s Department of Anthropology, and senior author of the paper, commented that the study provides valuable insights into maternal health in the postpartum period. She also hopes that this study will lead to further research in this area. She emphasized that this study offers a rare in-depth look at immunity from the postpartum mother’s perspective.The research on the impact of breastfeeding has mainly focused on the benefits for the infant, showing that it can improve the baby’s immunity and development. Additionally, mothers who breastfeed may have a lower risk of developing certain cancers and diabetes in the long run.
However, what about the effects on women in the crucial first months to years after giving birth? To explore this, Boddy, lead author and co-Principal Investigator Carmen Hové and their team studied a group of 96 women in the Seattle area who had given birth within the previous six months. The researchers collected saliva samples from the women twice over a 24-hour period, once before bedtime, and The researchers found themselves in an unexpected but advantageous experimental situation due to the COVID-19 pandemic and lockdown. This allowed for controlled environments for the mothers, reducing the risk of infections that could affect immunity readings.
According to Boddy, the situation was a perfect natural experiment for studying immune function, as none of the participants were sick. The goal was to monitor the cyclical levels of five types of proteins (CRP, IL-1β, IL-6, IL-8, and TNF-α) that indicate inflammation, serving as markers of immune response.Boddy explained that breastfeeding triggers a range of inflammatory responses, which isn’t always a negative thing as it helps in remodeling and functioning of the breast. The concentration of proteins generally tends to be higher in the mornings and lower in the evenings. The researchers aimed to observe any abnormal protein levels and how they correlated with the feeding habits of new mothers. They found that some proteins showed no significant differences in their morning and evening levels regardless of the feeding strategies of the mothers.
After the mothers pumped or breastfed. However, for the C-reactive protein (CRP) the researchers found that levels peaked in the evenings for women who relied heavily on breastfeeding, reversing the normal diurnal trend.
“We expected that low rates of lactating would be associated with a relatively high morning peak in CRP and vice versa,”Hové said. “What we ended up finding is that among mothers who reported intensive lactation, via either breastfeeding or pumping, CRP was higher at nighttime.” More research is needed to determine the precise effects of this unique pattern in breastfeeding or lactating.mothers, she added.
“We don’t have a clear understanding of the situation,” Boddy stated, “it’s possible that not fully emptying your breast leads to inflammation.” Alternatively, the inflammation could be a natural response to pregnancy. It’s also possible that incomplete emptying is a result of stress. This stress may be caused by the interrupted sleep that comes with round-the-clock breastfeeding schedules. “We can’t determine the exact cause and effect; it’s just a correlation,” she explained. “This study demonstrates a distinct immune profile, and we need to further examine this.”
This study uncovers the fact that there is a unique immune profile as a result of breastfeeding and it needs to be studied in more depth.”The true complexity of postpartum breastfeeding is a significant part of the ongoing physiological negotiation between the mother and the new baby, which primarily benefits the infant, as mentioned by Boddy. She explained that there is a concept in evolutionary biology known as maternal-fetal conflict, where the baby always wants more than the mother has to give when there are two bodies in one maternal unit. This research explores the ambiguous area of postpartum health from the mother’s perspective, particularly focusing on breastfeeding and immunity. Despite the ideal scenario long advocated by organizations like the World Health Organization, it is crucial to acknowledge the challenges and intricacies involved.Researchers discovered that despite the common belief that breastfeeding is the best option, even well-educated and financially stable women in their study utilized a variety of feeding methods, which indicates the difficulties of exclusively breastfeeding. “There’s been a lot of pushback, mostly from lactating mothers, centered around time constraints. Our society doesn’t make it easy for us to actually breastfeed and have lactational support,” said Boddy, who nursed both her children as infants and found it “challenging to meet breastfeeding goals.” Moreover, there is a lack of clear guidelines on when breastfeeding should stop. The physiological and other factors that should determine the duration of breastfeeding remain unclear.The ongoing negotiation may lead to diminishing benefits for the mother, and this could last for years. Could this information provide insight into other trends, such as maternal mortality? The researchers are eager to delve deeper into the topic and analyze it on an individual level to uncover more patterns in postpartum health and breastfeeding. This includes looking at the different hormones involved in lactation. “I believe this study has raised more questions than it has answered. Our goal is to follow these women throughout their postpartum experience and see how it evolves,” Boddy explained. “It has always been a challenge to find the best way to do this, but it is crucial for the mother’s well-being.”The process of feeding our infants and the act of breastfeeding can be quite demanding.
