Today, there’s a huge movement touting the benefits of breastfeeding over formula feeding. Doctors say breastmilk gives infants better versions of the nutrients critical for brain development. They even say nursing helps reinforce instinctual bonds between mother and child. Some of these claims are largely intuitive. However, much of what we know today about maternal milk production has roots in one major breakthrough at Cold Spring Harbor Laboratory (CSHL).
Before the 1930s, the medical community obviously knew that lactation happened but didn’t know why. They had some curious ideas. Was the process spurred by something coming from the placenta? The ovaries? Or could it be the corpus luteum, a group of cells that forms during the menstrual cycle?
In 1933, biologist Oscar Riddle answered the question once and for all when he identified the hormone prolactin as the cause of lactation. This discovery not only helped land Riddle on the cover of Time magazine but also kicked off new fields of study about the hormone. In the following decades, researchers would find that prolactin plays a role in more than 300 bodily activities.
Riddle’s discovery is an early entry into a long line of women’s health breakthroughs at CSHL that continue today.
“This is a place where we are encouraged to take risks, ask questions, and look for problems that other places may not have the resources to explore,” says Camila dos Santos, a CSHL associate professor specializing in breast cancer. “The goal here is to provide information that the medical community doesn’t understand in terms of cancer risk. By doing so, we empower women to better understand their health and create avenues to develop preventative strategies.”
One question dos Santos’ lab asks is why breast cancer risk is lowered for people who experience pregnancy before the age of 25 and rises for those who get pregnant after 35. “If we can understand why young pregnancy decreases breast cancer risk, we can think about how to mimic that effect,” dos Santos says. Her lab has considered the roles that many different hormones may play here, including—you guessed it—prolactin.
CSHL Associate Professor Camila dos Santos speaks about her research on breast cancer prevention during a Cocktails & Chromosomes talk.
Understanding how women’s bodies change over the course of their lives is critical for breast cancer prevention. Despite mortality rates having dropped over the last two decades, more than 70% of women who develop breast cancer have no family history or genetic mutations known to predispose them to the disease. Instead, their risk may very well stem from life experiences.
“Pregnancy changes our whole body,” dos Santos explains. “Puberty changes our whole body. Menopause changes our whole body. By focusing on these life experiences, we can understand what changes and how it affects our cancer risk.”
Written by: Jen A. Miller | publicaffairs@cshl.edu | 516-367-8455