“This study suggests, for the first time, that vaginal douches may increase a women’s exposure to phthalates, chemicals that may alter hormone action and are associated with serious health problems,” said the senior author of the study Ami Zota, ScD, MS, an assistant professor of environmental and occupational health at Milken Institute School of Public Health (Milken Institute SPH) at the George Washington University and a former postdoctoral fellow at UC San Francisco. “These findings raise questions about the health and safety of vaginal douches and other fragranced products used in and around the vaginal area.”
Zota and other scientists at Milken Institute SPH led the study, which included Tracey Woodruff, PhD, MPH, a professor of obstetrics, gynecology and reproductive sciences and director of the Program on Reproductive Health and the Environment at UCSF.
Public health officials advise against the use of douching products, which can hide vaginal infections and lead to other serious health problems. Despite that, douching products are still a popular item on the drug store shelf and are disproportionately used by black women. The current study adds a new cause for concern over their widespread use.
Phthalates are found in many personal care items found in drug stores, and are associated with many health problems, including developmental and behavioral issues in children who have been exposed in the womb. One type of phthalate in particular—diethyl phthalate (DEP) is used in products to retain a fragrance. And since many feminine care products, including tampons, sanitary napkins and commercial douches, contain fragrance they may be an unrecognized source of exposure to phthalates—especially for women of reproductive age, Zota said.
Yet scientists have not looked at feminine care products to see if they expose women to this class of chemicals. To address that gap in the research, Zota and her colleagues studied 739 women age 20 to 49 who had participated in a national survey and had answered questions about their use of feminine hygiene products. The researchers knew that phthalates can be absorbed through the thin skin in the vagina and once in the body are excreted as metabolites. So the researchers also looked for phthalate metabolites in urine samples collected from the study participants.
The team found that douching was associated with higher urine levels of a metabolite of the phthalate DEP. In fact, women who reported douching in the past month had 52 percent higher urinary concentrations of this metabolite compared to women who never used these products.
The researchers also found a dose-response relationship between frequency of douching and phthalate body burden. Women who douched frequently had the highest exposure. They found that women who reported using these products two or more times a month had 152 percent higher urinary concentrations of the DEP metabolite than non-users.
Black women appear to be at higher risk for phthalate exposure because, according to the study, they use douching products more often than white or Latino women. Nearly 40 percent of the black women in this study reported douching in the previous month compared with just 14 percent and 10 percent of white or Mexican American women, respectively.
The study confirms other research, which shows that black women tend to have higher concentrations of the DEP metabolite in their urine. That finding raises the concern that black women may be at increased risk of health problems due to phthalate exposure, Zota said.
The current study did not directly tie phthalates in douching products to health problems in women—additional research will have to make that direct connection, Zota said. Still, the research did find that vaginal douching may increase a woman’s exposure to DEP and that’s a troubling finding that needs to be explored further, she said.
The American College of Obstetrics and Gynecology and other health experts recommend against douching because this practice has been associated with increased risks of vaginal infection, pelvic inflammatory disease, problems during pregnancy and sexually transmitted diseases. Now, this study adds the worry that douching may also expose women to chemicals that can lead to health problems later in life or can harm their developing baby—if women are pregnant while using such products.
“This study offers another piece of scientific evidence that shows why we need to know more about chemicals and their health risks before they get into our bodies,” said UCSF’s Woodruff. “It’s critical that we have public policies to ensure that the products marketed in the United States are safe.”
The study looked at associations between phthalates and six different types of feminine hygiene products, including tampons, sanitary napkins, feminine sprays and wipes, but only found an association with vaginal douches.
Other authors of the study include Francesca Branch and Susanna Mitro, both at the Milken Institute SPH.
About Milken Institute School of Public Health at the George Washington University
Established in July 1997 as the School of Public Health and Health Services, Milken Institute School of Public Health is the only school of public health in the nation’s capital. Today, more than 1,700 students from almost every U.S. state and 39 countries pursue undergraduate, graduate and doctoral-level degrees in public health. The school also offers an online Master of Public Health, MPH@GW, and an online Executive Master of Health Administration, MHA@GW, which allow students to pursue their degree from anywhere in the world.
UC San Francisco (UCSF) is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. It includes top-ranked graduate schools of dentistry, medicine, nursing and pharmacy, a graduate division with nationally renowned programs in basic, biomedical, translational and population sciences, as well as a preeminent biomedical research enterprise and two top-ranked hospitals, UCSF Medical Center and UCSF Benioff Children’s Hospital San Francisco.