Triclosan, a popular antimicrobial ingredient found in over 2,000 consumer products such as soaps, toothpastes, cosmetics, and even furniture and toys, might be linked to colon inflammation according to a recent study published in the Science Translational Medicine Journal.
The study, published on May 30, used mice as subjects to see how “brief exposures of triclosan could affect inflammation.” In order to create conditions comparable to humans who had been using toothpaste with triclosan for two weeks, the mice were fed water with triclosan for three weeks. All mice experienced colon issues, ranging from inflammation to diarrhea to rectal bleeding. The gut microbiome of the mice was found to be depleted of healthy bacteria called Bifidobacterium associated with anti-inflammation. In mice already with colon cancer, triclosan was linked to exacerbating tumor development. According to Haixia Yang, the lead researcher from the University of Massachusetts Amherst, triclosan exposure “could cause adverse effects on colonic inflammation and colon cancer.” The study is unique because it is among the few to analyze triclosan at more typical levels of exposure, comparable to that in humans.
As it stands, triclosan is still allowed in oral hygiene products such as toothpaste since it has been shown to effective in preventing gingivitis. However, triclosan was among 23 other ingredients that were banned in over-the-counter anti-bacterial soaps and body washes in a final ruling in 2017 by the U.S. Food and Drug Administration (FDA). As Janet Woodcock, M.D., the director of the FDA’s Center for Drug Evaluation and Research (CDER), said, “Consumers may think antibacterial washes are more effective at preventing the spread of germs, but we have no scientific evidence that they are any better than plain soap and water…in fact, some data suggests that antibacterial ingredients may do more harm than good over the long-term.”
According to the FDA’s explanation, manufacturers could not provide the necessary evidence and data to prove that triclosan or the 23 other ingredients meet the “Generally Recognized as Safe and Effective” (GRAS/GRAE) standard in soaps and body washes. The FDA’s ban did not extend to the use of these products in health care settings.
Previous studies on the effects of triclosan have shown that high exposure can decrease levels of some thyroid hormones regulation in animals and may contribute to the development of antibiotic-resistant germs. There are more ongoing studies surrounding triclosan and its effects, including the likelihood of developing skin cancer after long-term exposure to triclosan in animals.
Doctors and researchers are still cautious about consumers buying products that contain triclosan. Consumers can absorb small amounts of triclosan through the skin and mouth, according to Dr. James Steckelberg. In a 2008 report using urine samples from U.S. children and adults, about 75 percent of samples were detected to have concentrations of triclosan. Additionally, in a 2016 article published by the American Chemical Society, triclosan is even found in household dust. As the FDA writes on its website, there is not sufficient evidence of the effects of triclosan on human health, and they “don’t have enough information available to assess the level of risk that triclosan poses for the development of antibiotic resistance.”
However, as a preemptive measure, companies have been phasing out triclosan in their products since the FDA’s proposed ban in 2013.
As the future of triclosan’s usage in commercial products is still unknown, Yang and her fellow researchers write, “further studies are urgently needed to better characterize the effects of [triclosan] exposure on gut health to establish science-based policies for the regulation of this antimicrobial compound in consumer products.”
Beyond Pesticides, a 501(c)(3) nonprofit organization based in D.C., has a list of products that contain triclosan on their website.
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