Since cancer seems to be an ever-present enemy, we greet
the appearance of its lethal emissaries in prosaic objects with a morbid
lack of surprise: carcinogens lurk in coffee, hamburgers, rugs,
dry-cleaned clothes, even peanut butter. And it may apparently reside in
one of the most popular toothpastes on the market, a toothpaste you’ve
probably thrown into your own shopping cart with nary a second thought.
The
possible culprit is the germicide triclosan, found in Colgate Total,
the widely-used brand manufactured by Colgate-Palmolive. Introduced in
1997, the manufacturer claims that it is the “only toothpaste approved
by the FDA to help fight plaque and gingivitis” by blasting the teeth
and gums with triclosan.
The claim is at least partly
true: no other toothpaste in the United States contains triclosan,
though plenty of antibacterial soaps and cosmetics count it as an
ingredient. It is that bacteria-fighting capability that has recently
raised questions about Colgate Total’s safety, as well as about whether
the Food and Drug Administration knuckled under and did not heed
warnings about the compound.
Triclosan is a chlorinated aromatic compound:
very basically, two benzene rings (a sturdy hydrocarbon, with six atoms
of carbon and hydrogen each) linked by an oxygen atom, with three
chlorine atoms protruding like spokes, as well as a lone hydroxyl group
(oxygen + hydrogen). First used in the 1970s in hospitals, it has since
become a widespread antimicrobial agent. Not only is triclosan present
in Colgate Total and many household soaps, but it can also be found in
coolers, odor-protected shoes and makeup, according to Mae Wu, a lawyer
with the Natural Resources Defense Council. She says that triclosan is
“all over the place,” even if, as she notes, we had “been doing fine
without it” for several centuries of human-microbial cohabitation of the
planet.
“Triclosan is 110 percent marketing,” says
Michael Osterholm, who heads the Center for Infectious Disease Research
and Policy at the University of Minnesota. Osterholm, who helped
Minnesota become the first state to ban most uses of triclosan. He told
me the compound has been superseded by superior, safer antimicrobial
agents, and Procter and Gamble has begun advertising its Crest
toothpaste as being “100% triclosan free.” That may also be a triumph of
marketing, but one that could lead more people to question the presence
of triclosan in household items, thereby forcing Colgate’s hand.
“They understand that the public is getting this,” Osterholm says of the Crest claim.
“Triclosan isn't an essential ingredient in many products,” writes Dr. James M. Steckelberg of the Mayo Clinic.
“While triclosan added to toothpaste has been shown to help prevent
gingivitis, there's no evidence that antibacterial soaps and body washes
containing triclosan provide any extra benefits, according to the Food
and Drug Administration.” On its website,
the FDA says that soaps that contain antibacterial compounds like
triclosan have not been shown to be “any more effective at preventing
illness than washing with plain soap and water.” The FDA stops well
short, however, of calling triclosan a danger, merely suggesting that
consumers think twice about buying products that contain it.
Earlier
this summer, the Society for Healthcare Epidemiology in America, whose
mission is to prevent hospital infections, made a blunt recommendation
to doctors in its guidelines for hospital hygiene:
“Do not use triclosan-containing soaps.” Those guidelines also cite
“concerns about the potential human and environmental impacts of this
chemical” and suggest, instead, the use of alcohol-based hand rubs.
The
FDA first promised to look at triclosan in handsoap in 1974. Four
decades later, that study remains incomplete, though it will reportedly
be released in 2016.
Meanwhile, most people are
absorbing triclosan whether they know it or not. Triclosan is nearly
ubiquitous, easily entering the body by ingestion or through the skin.
The Centers for Disease Control and Prevention tested 2,517 people in
2003 and found that almost three-fourths had triclosan in their urine.
Toothpaste is an especially potent triclosan-delivery vehicle. “People
who brushed their teeth with Colgate Total had more than five times as
much triclosan in their urine as people who didn’t use it,” Wu wrote in an NRDC blog post.
Far less clear is what triclosan does (or doesn’t do) to the human organism. For example, a review by scientists at the University of California at Davis
concluded that when it comes to triclosan and triclocarban, a
chemically related antibacterial agent, “the benefits may not be worth
the risks.” The researchers wrote that triclosan and triclocarban could
cause neural and cardiac ailments, though they also conceded that “the
research is in its early stages."
Other recent research suggests that triclosan could cause breast cancer,
though the results were gleaned from exposure in mice. Triclosan’s
effects on the endocrine system, which delivers hormones throughout the
body, are also increasingly thought to be harmful; a 2006 study of bullfrogs and tadpoles exposed to triclosan in aquatic environments
found that “exposure to low levels of triclosan disrupts thyroid
hormone-associated gene expression and can alter the rate of thyroid
hormone-mediated postembryonic...development.” If triclosan does turn
out to be an endocrine disruptor, that would make young children,
infants and pregnant women especially vulnerable. (There are also
concerns about the accumulation of triclosan in waterways, where its
build-up could “disrupt aquatic life by changing native bacterial
communities,” according to aquatic ecologist Emma Rosi-Marshall.)
And
though the FDA is now urging Americans to think about their triclosan
consumption, the agency didn’t seem nearly as concerned with the issue
17 years ago, when it declared Colgate Total ready for supermarket
shelves. In 2010, the Natural Resources Defense Council sued the FDA for
access to documentation regarding Colgate Total’s approval; the
documents, totalling 35 pages, had never been seen by the public before.
Bloomberg News had three scientists examine the FDA’s approval of Colgate Total.
“The recently released pages, taken alongside new research on
triclosan, raise questions about whether the agency did appropriate due
diligence in approving Total 17 years ago, and whether its approval
should stand in light of new research,” Bloomberg concluded in its
extensive investigation.
“The literature is all over
the place,” admits Rear Admiral Sandra L. Kweder, who is the deputy
director of the FDA’s office of new drugs. She says that the burden is
on soap manufacturers to show that their product is safe and efficient.
Industry
lobbyists do have complexity on their side: given the number of
chemicals to which the average person is exposed, and the genetic
disposition some people have to cancer, it is exceedingly difficult to
make a direct epidemiological correlation between household products and
incidences of cancer. Even with well-known villains like bisphenol-A
(BPA) and phthalates, the science remains in dispute.
Some
aren’t waiting for a resolution that could come in the distant future.
Earlier this year, Minnesota became the first state to prohibit usage of
triclosan, though FDA-approved products like Colgate Total are outside
the purview of the ban, which doesn’t take effect until 2017.
Colgate-Palmolive
says its product is safe. Patricia Verduin, Colgate-Palmolive’s head of
research and development, sent me an extensive rebuttal of several
studies that seem to show triclosan’s potential dangers. She noted that
90 studies, involving a total of 20,000 people, have made Colgate Total
“the most extensively tested and reviewed toothpaste in the world.” She
added that studies linking the compound to cancer and thyroid problems
“use excessively high levels of triclosan — in some instances, thousands
of times greater than the level of exposure from use of consumer
products.” Verduin also pointed out that “regulatory authorities around
the world… affirm that triclosan as used in consumer products is not a
human carcinogen or endocrine disruptor.”
And in an op-ed she wrote for Fox News,
Verduin maintains that “[r]ecent claims that triclosan in Colgate Total
can lead to cancer are absolutely untrue.” She discounts findings about
triclosan’s potential endocrine disruption as “rumors.”
Yet if the battle over BPA (which also has its defenders)
is any indication, triclosan will probably meet with a rising tide of
public suspicion, and more and more products will appear with green
stickers proclaiming themselves triclosan-free, as Crest already does.
Many major corporations have removed triclosan from soaps and cosmetics.
Others will likely follow, if for no other reason than for an image of
healthful living.
Triclosan may be falling out of favor,
but, for some, the underlying concern is that of federal regulators too
easily convinced by science done not in the public interest, but for
the sake of corporate gains. Writing last year in a New York Times op-ed,
investigative reporter Ian Urbina noted that federal regulators
effectively allow industry to police itself, so that few of the 85,000
industrial chemicals in use today — including the ones on your bathrooms
shelves — have passed unbiased governmental inspection. “Unlike
pharmaceuticals or pesticides,” Urbina writes, “industrial chemicals do
not have to be tested before they are put on the market. Under the law
regulating chemicals, producers are only rarely required to provide the
federal government with the information necessary to assess safety.”
But
for others, the chemicals aren’t dangerous if used with moderation. Dr.
Bruce D. Hammock, for example, runs the Laboratory of Pesticide and
Biotechnology at UC Davis and was one of the investigators involved in
the study on triclosan and triclocarban. “There are real risks to
triclosan,” Hammock says. “And there are real benefits.” He welcomes
more research into its effects on the human body.
Hammock
calls triclosan “quite a good antimicrobial” that belongs in the
hospital, not on the kitchen counter. “There’s no reason for it to be
there,” he says of its inclusion in hand and dish soaps.
Toothpaste
is another matter, and Hammock points out that the concentration of
triclosan is low in Colgate Total, while, at the same time, the
incidence of gingivitis is high enough to warrant the compound’s
inclusion. Hammock adds that he is happy with his toothpaste of choice:
Colgate Total.
Regulators share his confidence. Jeff
Ventura, a press officer for the FDA, sent me a statement asserting that
“based on the scientific evidence, in this case, the balance of benefit
and risk has been shown to be favorable for [Colgate Total].” The
statement does also say, however, that “use of an ingredient may be
acceptable for one product but not for another,” thus perhaps opening
the way for a ban of triclosan in soaps. After all, federal regulators
can’t ignore growing concerns buttressed by mounting evidence.
Asked if the FDA would revisit its approval of Colgate Total, Dr. Kweder hesitates.
“1997 was a long time ago,” she says.
