Exposure to common chemical during pregnancy may reduce protection against breast cancer 懷孕期間接觸普通化學品可能會降低對乳腺癌的保護

EWS RELEASE 16-MAR-2021

Jkzx.com’s editor’s note: Pregnancy is supposed to render some protection against breast cancer. So if pregnant women are exposed to the chemical called propylparaben, then this endocrine disruptor can boost the breast cancer risk. So overall, the pregnancy may not bring pregnant women much benefits due to the exposure.

Remember that other types of similar chemicals as long they are called parabens may have the similar detrimental effect on the risk of breast cancer. So be careful and minimize your exposure to these endocrine disruptors.

Parabens can be found in a range of household products including personal care products like shampoos, conditioners, lotions, cleansers, shower gels, feminine hygiene products.

Jkzx.com的編者註：懷孕應該可以預防乳腺癌。 因此，如果孕婦暴露於對羥基苯甲酸丙酯中，這種內分泌干擾物會增加患乳腺癌的風險。 因此，總的來說，由於暴露，懷孕可能不會給孕婦帶來很多好處。 請記住，其他類型的類似化學物質（只要被稱為對羥基苯甲酸酯）可能會對乳腺癌的風險產生類似的有害影響。 因此，請小心並儘量減少與這些內分泌干擾物的接觸。 對羥基苯甲酸酯可以在一系列家用產品中找到，包括洗髮水，護髮素，乳液，清潔劑，沐浴露，女性衛生用品等個人護理產品。

UMass Amherst research suggests propylparaben is an endocrine disruptor

UNIVERSITY OF MASSACHUSETTS AMHERST

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Low doses of propylparaben – a chemical preservative found in food, drugs and cosmetics – can alter pregnancy-related changes in the breast in ways that may lessen the protection against breast cancer that pregnancy hormones normally convey, according to University of Massachusetts Amherst research.

The findings, published March 16 in the journal Endocrinology, suggest that propylparaben is an endocrine-disrupting chemical that interferes with the actions of hormones, says environmental health scientist Laura Vandenberg, the study’s senior author. Endocrine disruptors can affect organs sensitive to hormones, including the mammary gland in the breast that produces milk.

“We found that propylparaben disrupts the mammary gland of mice at exposure levels that have previously been considered safe based on results from industry-sponsored studies. We also saw effects of propylparaben after doses many times lower, which are more reflective of human intake,” Vandenberg says. “Although our study did not evaluate breast cancer risk, these changes in the mammary tissue are involved in mitigating cancer risk in women.”

Hormones produced during pregnancy not only allow breast tissue to produce milk for the infant, but also are partly responsible for a reduced risk of breast cancer in women who give birth at a younger age.

The researchers, including co-lead author Joshua Mogus, a Ph.D. student in Vandenberg’s lab, tested whether propylparaben exposure during the vulnerable period of pregnancy and breastfeeding adversely alters the reorganization of the mammary gland. They examined the mothers’ mammary glands five weeks after they exposed the female mice to environmentally doses of propylparaben during pregnancy and breastfeeding.

Compared with pregnant mice that had not received propylparaben, the exposed mice had mammary gland changes not typical of pregnancy, the researchers report. These mice had increased rates of cell proliferation, which Vandenberg says is a possible risk factor for breast cancer. They also had less-dense epithelial structures, fewer immune cell types and thinner periductal collagen, the connective tissue in the mammary gland.

“Some of these changes may be consistent with a loss of the protective effects that are typically associated with pregnancy,” says Mogus, who was chosen to present the research, deemed “particularly newsworthy” by the Endocrine Society, at the international group’s virtual annual meeting, ENDO 2021, beginning March 20.

Mogus says future studies should address whether pregnant females exposed to propylparaben are actually more susceptible to breast cancer. “Because pregnant women are exposed to propylparaben in many personal care products and foods, it is possible that they are at risk,” Mogus says, adding that pregnant and breastfeeding women should try to avoid using products containing propylparaben and other parabens.

“This chemical is so widely used, it may be impossible to avoid entirely,” Mogus adds. “It is critical that relevant public health agencies address endocrine-disrupting chemicals as a matter of policy.”

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This research received funding from the University of Massachusetts Commonwealth Honors College Grant, the Endocrine Society’s Summer Research Fellowship and the National Institutes of Health.

Other study co-authors are Charlotte LaPlante, Ruby Bansal, Klara Matouskova, Shannon Silva, Elizabeth Daniele, Mary Hagen and Karen Dunphy, all of UMass Amherst; Benjamin Schneider and Sallie Schneider of Baystate Medical Center in Springfield, Mass.; and D. Joseph Jerry of UMass Amherst’s Department of Veterinary and Animal Sciences and Pioneer Valley Life Sciences Institute in Springfield.