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What’s really in soap? Study finds harmful chemicals

Source: Lisa Marshall | Natural Foods Merchandiser

A decades-old chemical found in most deodorant and antibacterial bar soaps could be harmful to nursing babies when mom uses it, according to a new University of Tennessee study conducted in rats.The study, unveiled at the Endocrine Society’s annual meeting in June, found that when female rats were fed triclocarban (TCC)— a ubiquitous bactericide found in antibacterial bar soap, deodorant and wipes—pups who nursed from them gained less weight and were significantly less likely to survive.”This information provides supporting evidence for the potential adverse effects of TCC exposure during early life,” the study concluded. We asked lead author Rebekeh Kennedy, a UT graduate student pursing a master’s in public health and nutrition, how she did the study and what consumers should make of it.

Natural Foods Merchandiser: What does previous research say about triclocarban?

Rebekeh Kennedy: Research has shown it has the potential to disrupt the endocrine system—particularly thyroid processes. Research conducted at UT has also shown the chemical has the potential to increase sex organ weights in adult male rats. We wanted to see if such effects would be more profound if exposure occurred during pregnancy or nursing.

NFM: How did you do the study?

RK: We had three groups of pregnant rats: one control group; and two groups that were given different amounts of TCC in their food from day five of their pregnancy until postnatal day 21. The level of TCC found in the blood of the exposed maternal rats corresponded to levels in humans after a 5-minute whole body shower using a bar soap containing triclocarban. At birth, some pups were moved between each group so that each mother nursed some of her own pups as well as pups from the other two treatment groups. (This way, some pups were born of TCC- exposed mothers but nursed from mothers who were not exposed, and vice versa.) The offspring were weighed daily.

NFM: What did you find?

RK: No matter what group they were born to, if they nursed from TCC-supplemented rats, they were less likely to survive. In the medium group (nursing from moms supplemented with 0.2 percent TCC) only 13 percent of the pups survived, and they weighed roughly half that of the control group.In the high-dose group (nursing from moms supplemented with 0.5 percent TCC) none of the pups survived past day six. Meanwhile, 100 percent of the pups who nursed from the control moms  survived, regardless of their in-utero exposure.

NFM: Should nursing moms avoid antibacterial bar soap? 

RK: There is a time and place for antibacterial bar soaps, such as in health care settings where the chance of infection and transmission is high. Certain people, whose immune system is compromised, may also need them. But for the average person, antibacterial soap is no more effective than regular soap.

NFM: How can people avoid triclocarban?

RK: Just look on the ingredients list. If the soap contains it, the list may include “triclocarban.” If a label reads antimicrobial, it could be in there.

NFM: What is the take-home message?

RK: This is just one study. More research would be needed before applying these findings to humans. But I think the take-home message for nursing mothers and the general public is that they should be mindful of what they are putting on and in their bodies.This study and the ongoing review of triclosan (another antimicrobial found in liquid soap) by the Food and Drug Administration are bringing attention to the fact that there are products in everyday use that might have unintended effects.