Study: Antibacterial In Soap Causes Cancer
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Photo Credit: CDC |
Triclosan is an antimicrobial commonly found in soaps, shampoos,
toothpastes and many other household items. Despite its widespread use,
researchers at University of California, San Diego School of Medicine
report potentially serious consequences of long-term exposure to the
chemical.
The study, published on Monday by Proceedings of the National Academy of Sciences,
shows that triclosan causes liver fibrosis and cancer in laboratory
mice through molecular mechanisms that are also relevant in humans.
“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,” said Robert H. Tukey, PhD, professor in the departments
of Chemistry and Biochemistry and Pharmacology.
Researchers found
that triclosan disrupted liver integrity and compromised liver function
in mouse models. Mice exposed to triclosan for six months (roughly
equivalent to 18 human years) were more susceptible to chemical-induced
liver tumors. Their tumors were also larger and more frequent than in
mice not exposed to triclosan.
The study suggests triclosan may do its damage by interfering with
the constitutive androstane receptor, a protein responsible for
detoxifying (clearing away) foreign chemicals in the body. To compensate
for this stress, liver cells proliferate and turn fibrotic over time.
Repeated triclosan exposure and continued liver fibrosis eventually
promote tumor formation.
Triclosan is perhaps the most ubiquitous consumer antibacterial.
Studies have found traces in 97 percent of breast milk samples from
lactating women and in the urine of nearly 75 percent of people tested.
Triclosan is also common in the environment: It is one of the seven most
frequently detected compounds in streams across the United States.
“We could reduce most human and environmental exposures by
eliminating uses of triclosan that are high volume, but of low benefit,
such as inclusion in liquid hand soaps,” Hammock said. “Yet we could
also for now retain uses shown to have health value — as in toothpaste,
where the amount used is small.”
Triclosan is already under scrutiny by the FDA, thanks to its
widespread use and recent reports that it can disrupt hormones and
impair muscle contraction.
SOURCE: UCSanDiego