by Jessica Pasley
Researchers at the National Institute of Environmental Health Sciences (NIEHS), with the help of an epidemiologist at Monroe Carell Jr. Children’s Hospital at Vanderbilt, recently published findings showing an association between infant soy formula feeding and menstrual pain in adulthood.
The report adds to the increasing evidence lending support to the reproductive health consequences of early-life exposure to soy formula.
“Soy protein contains phytoestrogens, or plant-based compounds that demonstrate estrogenic activity in experimental animal models,” said Margaret Adgent, PhD, MSPH, research assistant professor of Pediatrics at Vanderbilt. “Infants who are fed soy formula can be exposed to substantial amounts of these compounds.
“Because an infant’s reproductive system is developing well into the postnatal period, it is important to investigate whether this type of exposure is related to early reproductive development as well as long-term reproductive health.
“This study provides some evidence that an exposure occurring during infancy may increase a woman’s risk of experiencing menstrual pain as an adult,” she said.
“This is important because early-life factors are not commonly recognized as risk factors for adult reproductive health outcomes.”
The observational study was published online in the journal Human Reproduction. Scientists examined data from 1,553 African-American women who participated in a Study of Environment, Lifestyle & Fibroids (SELF) cohort.
According to data from animal studies, early-life exposure to genistein, a naturally occurring component in soy formula, can interfere with the development of the reproductive system and induce changes in reproductive tissues that persist into adulthood, some of which may be related to menstrual pain.
As a pediatric epidemiologist, Adgent’s work focuses on investigating how early life environmental and nutritional exposures can influence children’s health and development. With an interest in exposures to endocrine disrupting compounds, or chemicals that can alter the way hormones are produced and function in the body, Adgent was drawn to the soy formula study.
She collaborated with scientists at NIEHS, part of the National Institutes of Health (NIH), to interpret the SELF study findings and provide input on the plausibility of the association between soy formula and menstrual pain.
Adgent hopes the recent findings, coupled with similar results from a prior study, will inspire additional research efforts in different study populations to further explore the association observed by the team.
“Not a lot is known about how soy exposure in infancy can affect health and development,” she said. “I would like to see more in-depth investigations that take a closer look at the potential mechanisms or pathways to help us understand the biologic processes that link soy formula and menstrual pain.
“Ideally, subsequent studies will follow young people into adulthood as well as explore specific mechanisms — epigenetic modification or gene expression — that link soy phytoestrogens to menstrual pain.”
