What used to be much cited in marketing ads of antibacterial soaps and other cleaning products has now become associated with depreciating health. Known for its cleansing properties, triclosan has become a normal staple in cleaning products such as liquid soaps, acne lotion, toothpaste, etc. But what people are starting to find out is that this cleaning agent is as toxic to the body as it is to microbes. And a new study reveals yet another of triclosan's dark secrets: its long-term use may promote the growth of cancerous tumors in lab mice.
Published in Proceedings of the National Academy of Sciences, the new study used mice that were exposed to triclosan for six months, or an equivalent of 18 years for humans. The mice with such exposure had more liver fibrosis (hardened tissues) and cancer. Mice also had larger and more frequent tumors when they were exposed to triclosan. Some of those mice had kidney fibrosis, too, according to the study.
"Triclosan's increasing detection in environmental samples and its increasingly broad use in consumer products may overcome its moderate benefit and present a very real risk of liver toxicity for people, as it does in mice, particularly when combined with other compounds with similar action," says study leader Dr. Robert H. Tukey, professor in the departments of Chemistry and Biochemistry and Pharmacology at the University of California, San Diego School of Medicine.
"If you have a damaged cell that's been attacked by a mutagen, triclosan promotes the development of the tumor. The compound also causes inflammation, which means that all the ingredients necessary for developing cancer are present," Tukey adds.
Compared to control mice, those exposed to triclosan grew tumors that were larger and more frequent. Triclosan may wreak such havoc by interfering with the protein that detoxifies chemicals in the body, the study says.
Researchers also found that in addition to causing liver fibrosis, triclosan caused some kidney fibrosis.
"There are really not a lot of environmental agents that have the potential to cause kidney fibrosis," Tukey says. "It definitely is doing some nasty stuff with long-term exposure in these mice."
"It has also contaminated virtually all of the waterways in the United States, many in the world. It's the major contaminant in sediment in most lakes. It's present really everywhere."
Previous studies on triclosan revealed that it impairs muscle contraction in cells, and it has also been linked to endocrine disruption and bacterial resistance. Other research has warned against pregnant women using triclosan for fear that it will disrupt fetal development. The chemical has also been linked to sperm trouble.
The U.S. Food and Drug Administration is reviewing triclosan after multiple reports of its possible dangers.
