Have you ever wondered what happens to your breasts after you stop nursing? If so, here's your answer—and it has an amazing link with finding a cure for breast cancer.

By Zara Husaini Hanawalt
December 11, 2018
breasts as melons in bra
Credit: Kaspars Grinvalds/Shutterstock

You're probably well aware of the changes your breasts undergo when it's time for you to breastfeed—but do you know how they change when you've finished nursing? One 2016 study is giving us a better idea of the changes that occur within the breasts when they stop producing milk, and the findings are pretty surprising.

According to the study, which comes from The University of Manchester, the milk-producing cells in the breast are actually cannibalized by other cells in the body. It sounds gruesome, sure, but it does explain why many moms no longer produce milk after a period of not breastfeeding.

How do those dead mammary cells and leftover milk exit the body? That's unclear, according to the study's authors.

The study points out that women create up to a liter of breastmilk a day (that's 33 oz for all you pumping mamas), and the breasts produce a specific tissue so that the cells are able to make this milk. The process in which the milk-creating cells are killed off is called "apoptosis." Researchers are amazed that this process doesn't lead to inflammation, significant tissue damage or pain. 

“Immune-cell phagocytosis might be extremely painful and damaging. So we thought something else must be standing in for the immune cells. What we didn’t expect to find was a molecular switch that turned milk-secreting cells into cannibalistic cell eaters. We discovered that these cells were now able to eat or otherwise remove vast quantities of redundant milk-producing cells," Nasreen Akhtar, Ph.D., a researcher involved with the study said.

The good news? This finding could help doctors treat breast cancer through a similar process. The Rac1 signaling protein appears to be involved in the cannibalizing process, and this may also play a role in breast cancer development. I"n the future, there may be completely new ways to treat breast cancer," said Charles Streuli, a professor of cell biology at The University of Manchester, who supervised Akhtar's work. "If normal breast cells can eat their slightly altered neighbours, could we find a way to get healthy cells to consume and destroy all the cancer cells?"

Fit Pregnancy