News Coverage
Is Chemical in Breast Milk a Concern?
Experts Recommend Moms Continue to Breastfeed
Published September 23, 2003
What is the experts' advice to America's nursing mothers who heard that their breast milk contains the world's highest levels of a controversial chemical used as a fire-retardant?
Relax, and continue to breastfeed.
Fears on the safety of breastfeeding recently erupted, with two studies showing that the breast milk of each woman tested in the U.S. had high levels of polybrominated diphenyl ethers, or PBDEs, that are commonly used in furniture, electronic equipment, and other products in the typical home and workplace.
Brain Damage Seen in Mice
One study released this week by the Environmental Working Group, a nonprofit organization dedicated to reducing pollutants in air, water, and food, shows the average level of PBDEs in the 20 women tested was 75 times higher than what was detected in a previous study on Swedish women. The group says levels in those American women, living in 14 states, are similar to those suspected of causing brain damage and other problems in laboratory mice.
That report follows a study in the Aug. 7 issue of the journal Environmental Health Perspectives on 47 nursing mothers in Texas, noting that their breast milk had PBDE levels between 10 to 100 times higher than what has been found in previous studies on European women, where the chemicals have been banned. That research, done at the University of Texas School of Public Health, was also funded by private environmental groups.
Keep Breastfeeding, Experts Recommend
But experts tell WebMD there is no reason to believe that breast milk is harmful to babies or shouldn't remain as their best source of nutrition.
"I regret that this is front-page news because it's really frightened everyone," says Cheston Berlin, MD, professor of pediatrics and pharmacology at Hershey Medical Center in Pennsylvania and a recognized expert on chemicals found in breast milk. "I've just had two mothers tell me that if they knew about this before, they never would have breastfed. That's certainly not the message that I want to get out."
Berlin says that despite these findings, breastfeeding is still the preferred method for nourishing infants and should be the "enthusiastic" choice for mothers capable of doing it.
"Of course, there is concern for PBDEs, just as there's concern over the 500 different compounds in tobacco smoke and thousands of other chemicals in the environment," he tells WebMD. "But I don't know of any documented problems with bromated flame retardants in terms of exposure to an infant. And what I find interesting is that what is missing from these discussions is the fact that nobody has measured these PBDEs in infant formula, or what they may do during pregnancy."
One explanation: Breast milk is the easiest way to measure levels of any chemical accumulating in the human body. That's because when we inhale, eat, or otherwise absorb various environmental substances, they accumulate in fat cells -- and breast milk is loaded with fat sources from the nursing mother.
"If you wanted to test chemical exposure in people who aren't breastfeeding, you'd have to a do punch biopsy and sample their fat, which is pretty invasive," says Ruth Lawrence, MD, a renowned breastfeeding researcher at the University of Rochester School of Medicine who leads the toxicology committee of the Academy of Breastfeeding Medicine.
"It's not that breast milk contains higher amounts of these or other chemicals. Rather, breast milk is specifically measured because it's an easily attained marker, a way of measuring levels of these and other chemicals to determine exposure in the general population," she tells WebMD.
"Unfortunately, the way these findings can come across is that human milk is contaminated. But unless you measure fat levels of women who wind up bottle-feeding with biopsies, you can't determine how much of PBDEs are being passed onto the child. Or for that matter, how PBDEs accumulate in anyone else."
Her advice: "I certainly wouldn't suggest for one minute that you shouldn't breastfeed or that the theoretic risk of passing a few more nanograms of this chemical to your baby outweighs the tremendous benefit of breastfeeding."
Chemical's Effects Unknown
Exactly how, or even if, PBDEs harm humans is unknown, but previous research shows that in animals, high and long-term exposure can cause permanent learning, memory, and thyroid impairment, birth defects, and other problems. Because they are similar to other substances already banned in the U.S., the Environmental Working Group and other environmentalists say they may pose the same threat.
This is why PBDEs were specifically studied in the EWG study -- and not scores of other substances that could be in breast milk, says an organization spokeswoman.
"We're hoping the animal research on PBDEs doesn't convey to humans, but so much of this kind of research does," says the EWG's Lauren Sucher. "We still believe that women should continue to breastfeed. But we hope our study leads the U.S. government to follow the lead of Europe and California in banning these substances."
This summer, California announced it would give manufacturers until 2008 to find alternatives to using some PBDEs, which are added to make a wide range of products less likely to catch fire -- including computers, appliances, and car dashboards.
"It's tough to limit PBDE exposure since we're all going to watch TV and use computers and sleep in beds, and they can get in the body by inhaling them," Sucher tells WebMD. "We've done comparisons of some furniture in terms of their fire retardency of those treated and non-treated with these substances and didn't find a significant difference between them. So common sense suggests we may not even need them."