Disclosures: One study author reported providing paid expert assistance in legal cases involving PFAS-exposed populations. Timmermann reports no relevant financial disclosures.
September 16, 2021
2 min read

Common endocrine-disrupting chemicals may inhibit breastfeeding

Disclosures: One study author reported providing paid expert assistance in legal cases involving PFAS-exposed populations. Timmermann reports no relevant financial disclosures.
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Women exposed to higher concentrations of a class of endocrine-disrupting chemicals known as perfluoroalkyl and polyfluoroalkyl substances are at increased risk for terminating breastfeeding early, researchers reported.

Data show human exposure to perfluoroalkyl and polyfluoroalkyl substances (PFAS) may be associated with a range of adverse outcomes, including obesity, thyroid dysfunction and bone mineral density; however, mechanisms by which PFAS might affect breastfeeding are unknown. The class of more than 4,700 chemicals is used in everything from nonstick cookware to stain-resistant carpeting and firefighting foam.

Data were derived from Timmermann CAG, et al. J Clin Endocrinol Metab. 2021;doi:10.1210/clinem/dgab638.

“Breastfeeding is a vulnerable function that is affected by environmental factors like PFAS,” Clara Amalie Gade Timmermann, PhD, assistant professor at the University of Southern Denmark, told Healio. “Traditionally, early unwanted weaning has been ascribed to psychological factors, which are without a doubt important, but hopefully our research will help shift the focus and highlight that not all mothers can breastfeed despite good intentions and support from family and health personnel. Physiological factors are important for breastfeeding, and the environment that surround us affects our physiology.”

Timmermann and colleagues analyzed blood samples from pregnant women recruited from 2010 to 2012 to participate in the Odense Child Cohort. Researchers collected blood samples during late first trimester or early second trimester and measured levels of five major PFAS in 1,300 women — perfluorohexanesulfonic acid (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) — and prolactin concentrations in 924 women. Women subsequently provided information about the duration of breastfeeding in questionnaires at 3 and 18 months postpartum. A subgroup also provided breastfeeding information via weekly cellphone text messages. Researchers assessed associations between serum-PFAS concentrations and breastfeeding termination using Cox regression analyses and used linear regression to assess associations between serum-PFAS and prolactin concentrations.

Clara Amalie Gade Timmermann, PhD

The findings were published in The Journal of Clinical Endocrinology & Metabolism.

The median durations of any and exclusive breastfeeding were 33 weeks and 11 weeks, respectively. Researchers found each doubling in serum concentrations of PFOS, PFOA and PFNA increased the risk for terminating breastfeeding at any given time after birth by 16% (95% CI, 4-30), 14% (95% CI, 2-26), and 14% (95% CI, 3-27), respectively, while each doubling in the sum of the five PFAS increased the risk by 20% (95% CI, 6-36). There was no association between serum concentrations of PFOA, PFNA and PFDA and termination of exclusive breastfeeding; exclusion of women who did not initiate breastfeeding or terminated breastfeeding within the first week did not change the findings. Serum-PFAS concentrations were not associated with serum-prolactin concentrations.

The researchers noted that the findings are of public health importance due to global exposures to PFAS and the importance of breastfeeding to promote child and maternal health.

“Research that can help us understand the mechanisms by which PFAS affect lactation, as well as research on how other environmental factors might affect breastfeeding, are important, Timmermann told Healio.

In August, FDA released a report, reported by Healio, stating there was no evidence indicating that PFAS levels in processed foods warrant avoidance. The analysis, based on results from the FDA’s first survey of nationally distributed processed foods, showed 164 of 167 food items had “no detectable levels of PFAS,” the FDA said. The three foods that did have detectable levels were fish sticks, canned tuna and protein powder.

For more information:

Clara Amalie Gade Timmermann, PhD, can be reached at atimmermann@health.sdu.dk; Twitter: @cagtimmermann.