Toothpaste agent may do harm
MASSACHUSETTS: Triclosan, an antimicrobial agent found in toys, toothpaste, cosmetics and many other products, has been found to wreak havoc on the guts of mice whose blood concentrations of the compound are roughly equivalent to a typical level for humans.
One group of mice who were fed a diet laced with triclosan for three weeks ended up with lowgrade inflammation of the colon and saw their garden of gut microbes become notably depleted. Triclosan also made inflammatory bowel disease and colon cancer in mice worse.
The study authors, led by Haixia Yang, a postdoctoral food science researcher at the University of Massachusetts Amherst, discovered that the guts of triclosanfed mice were particularly depleted of Bifidobacterium, a strain that has been shown to have antiinflammatory effects.
By changing the gut’s microbiotic population and activating genes that govern inflammation and cancer growth, triclosan ‘‘could cause adverse effects on colonic inflammation and colon cancer,’’ Yang and her colleagues wrote. ‘‘Further studies are urgently needed to better characterise the effects of (triclosan) exposure on gut health to establish sciencebased policies for the regulation of this antimicrobial compound in consumer products.’’
Previous research has demonstrated triclosan’s toxicity at doses that would be unusually high for humans, but the new study is among the first to rigorously explore the compound’s safety at more typical levels of exposure.
Triclosan is routinely used in many toothpastes since it has been found to prevent gingivitis. Researchers have found evidence it settles and accumulates in household dust, extending humans’ exposure.
At high doses, triclosan is associated with a decrease in the levels of some thyroid hormones, at least in animals. Other studies have raised concern that exposure to triclosan increases the likelihood that bacteria will develop resistance to antibiotics. Researchers are also exploring whether longterm triclosan exposure increases risk for skin cancer.
Last June, 200 scientists and medical professionals signed the Florence statement, calling triclosan and a related agent, triclocarban, ‘‘environmentally persistent endocrine disrupters that bioaccumulate in and are toxic to aquatic and other organisms’’.
The group called for ‘‘greater transparency’’ in their use, adding that ‘‘they should only be used when they provide an evidencebased health benefit.’’ — TCA