By Kara Morris
TUESDAY, Nov. 15, 2022 (HealthDay News) — Uterine fibroids can cause uncontrolled bleeding and infertility in women, and now a new study finds an unexpected cause: toxic chemicals called phthalates found in everything from fast food packaging to plastic water bottles. .
“We detected DEHP phthalates and their degradation products in much higher amounts in the urine of women who also had symptomatic uterine fibroids. We then asked the question whether this association was causal. The answer was yes,” said study author Dr. Serdar Bolun, chair of the Department of Obstetrics and Gynecology at the College of Feinberg School of Medicine at Northwestern University in Chicago.
Up to 80% of women develop one or more fibroids in their lifetime, and some experience bleeding, anemia, miscarriage, and infertility. Most of them are not cancerous.
In the study, the researchers tested primary cells isolated from women’s fibroids. The researchers found that something known as MEHHP, which is a breakdown product of DEHP, activated a specific cellular pathway that led to tumor growth.
While previous studies have shown a consistent association between phthalate exposure and fibroid growth, this finding explains how this might happen.
DEHP is still widely used in the United States, even as there are concerns about its effect. It is gradually released into dust and air, landing on various surfaces.
Fibroids can be found incidentally during a caesarean section or scan, as well as discovered after symptoms appear, said Dr. Nathaniel Dinicola, an environmental health expert with the American College of Obstetricians and Gynecologists.
What causes these tumors in the first place is not fully understood.
It’s normal for cells to go through pre-programmed cell death, DiNicola explained, as most adults have somewhere around 50 million cells going through this cell death every day. When they don’t die and instead grow, they can cause fibroids or cancer.
DiNicola said, based on this study and previous research, he believes it is likely that these chemicals contribute to fibroids.
He noted that the study’s strength lies in its use of urine samples from real patients, not animal models.
“When they were comparing the association between fibroids and this exposure, they obtained a biological sample directly from the patient,” DiNicola said. “So, this is strength.”
However, this was not a randomized controlled trial, which is considered the gold standard for such research.
The good news, DiNicola said, is that when the researchers looked at the association, they found a U-shaped curve. With certain levels of exposure, the risk was higher.
“But on the low end, you might look at that for maybe some grace with these exposures,” he explained. “It’s really hard to claim, for example, not to be exposed to something that’s as ubiquitous as a chemical found in plastics and personal care products, phthalates.”
But he noted that people may be able to reduce their exposure. Doctors can instruct patients on ways to reduce exposure to phthalates in the same way they do with nutrition.
Policymakers can also regulate personal care products, especially beauty products, with an eye toward reducing racial disparities. DiNicola pointed to previous research that found that products advertised to women of color contain disproportionately high levels of phthalates.
For individuals looking for ways to reduce exposure in their personal care products, look for ones that specifically say they are phthalate-free, he suggested. Look for products that are fragrance-free rather than those labeled “unscented,” which may still use phthalates to bind different scents to cancel out the obvious scent. DiNicola said people should also avoid heating their food with plastic.
“I think it’s plausible that it would be impossible” to completely eliminate phthalates through procurement, DiNicola said, but “we want as little as possible.”
Bolon recommended staying away from plastic bottles or plastic food packaging, and using glass containers instead. It is advised not to use PVC products.
Polon added that policymakers could also advocate for and fund more research and legislation, as well as bans on plastic bags and bottles.
“In my opinion, this is the most impactful area to look at in terms of human health. This is a very understudied area.
Polon suggested that the pathway the researchers discovered could be targeted by new treatments for uterine fibroids.
Uterine fibroids need the hormones estrogen and progesterone to grow. He said scientists and clinicians should continue to search for alternative temporary measures with fewer side effects to help women reduce ovulation at times when they are not interested in becoming pregnant.
“Essentially, uterine fibroids don’t develop without frequent bouts of ovulatory cycles,” Bolon explained.
The results were published online on November 14th Proceedings of the National Academy of Sciences.
The US Office of Women’s Health provides more information about uterine fibroids.
SOURCES: Serdar Bulun, MD, chair of the department of obstetrics and gynecology, Northwestern University School of Medicine, Feinberg, Chicago; Nathaniel DiNicola, MD, environmental health expert, American College of Obstetricians and Gynecologists and Obstetrician/Gynecologist, Johns Hopkins Health System, Baltimore; Proceedings of the National Academy of SciencesNovember 14, 2022, online