Crane your head in any direction as you pass through your nearest pharmacy and you’ll be sure to come across the word “antibacterial” plastered on many a common household item, most notably hand soaps and body washes.
But while modern day antibacterial soaps have been marketed since the 1980s as the superior germ-fighting version of their Plain Jane counterparts, the last few years have seen a growing debate surrounding their effectiveness and even their safety. That debate has largely centered around the chemical triclosan, an antimicrobial that’s also found its way into everything from toothpastes to pet shampoo. A close cousin, triclocarban, is found in antibacterial bar soaps.
In 2014, Minnesota became the first state to outrightly ban retailers from selling “any cleaning product that contains triclosan and is used by consumers for sanitizing or hand and body cleansing,” save those products that have received express over-the-counter approval from the Food and Drug Administration (FDA) — a list that includes Colgate-Palmolive’s Total brand of toothpaste. The FDA announced in 2013 that it would take a closer look at triclosan.
Since 1994, the FDA has labeled consumer soaps containing triclosan under the “generally recognized as safe” category, which requires no clinical testing before they’re released to the public. Their new proposed rule, however, would require manufacturers to pass a higher bar before approval, or either relabel or reformulate their products completely. The agency’s final decision, issued through a definitive policy statement or monograph, is set to be released in September.
“Antibacterial soaps are used extensively by millions of consumers, and people may be exposed to these products repeatedly, on a daily basis over the course of their lifetime,” the FDA said in an email to Medical Daily. “Because of this extensive exposure, we believe that any potential risk from the use of an antiseptic wash should be balanced with a clearly demonstrated benefit.”
In the meantime, we here at Medical Daily have decided to pick the brain of an expert on the subject — Dr. Allison E. Aiello, an epidemiologist at the University of North Carolina — in order to detail what the fuss over triclosan and its ilk is really about.
Too Similar For Its Own Good
The trouble with triclosan is two-fold.
For one, while triclosan isn’t considered an antibiotic, it shares a lot in common with them — a little too much actually.
“Research shows triclosan does work somewhat similarly to antibiotics, in that it has a specific mechanism in the way it attacks bacteria called the enoyl-acyl carrier protein reductase [enzyme],” Aiello told Medical Daily, further noting that it can damage fungi and viruses in nonspecific ways. Triclosan inhibits this enzyme, which is found in some but not all bacteria like E. coli, stopping the bacteria from growing any further by interfering with its ability to produce a sturdy cell wall.
Bacteria are nothing if not survivors, though, and some eventually develop resistance to triclosan by buffing up their defenses. Unfortunately, because many antibiotics like isoniazid also target that particular enzyme, these bacteria inadvertently become resistant to them too. It can also coax other indirect changes from bacteria that “basically turn on mechanisms that would allow cross-resistance to the antibiotics we take for human disease,” Aiello added. An example of these changes is the sprouting of efflux pumps that enable bacteria to vomit back out antibiotics before they can kill them.
“We already have quite high levels of antibiotic resistance out there in the community, issues with multidrug resistance, so there’s a concern when you have ingredients” like triclosan in everyday life, said Aiello. The problem isn’t necessarily within our homes, since there’s limited evidence that our personal household use of triclosan triggers cross-resistance, but with the untold tons of triclosan that escape sewage treatment plants and are dumped in our lakes, rivers, and soil on a regular basis. In these environments, massive colonies of bacteria called biofilms clump together, and it’s feared that when these biofilms are constantly exposed to triclosan and other antibiotics, they gradually become stewpots of drug resistance.
Triclosan’s potential effect on bacteria has gotten plenty of growing scientific support over the years, but it still hasn’t been fully proven. For that matter, neither has the theory that it can otherwise cause human harm.
Studies have shown that triclosan can disturb hormone production and impair heart muscle activity; both seemingly worrisome considering that as much as 75 percent of people have at least trace amounts of the chemical in their bodies, according to the Centers for Disease Control and Prevention. But these studies have almost entirely been done with animals, and there hasn’t been any clear-cut evidence of these effects in people. That doesn’t mean it can’t harm us, it just means that we don’t really know yet.
“The relevance of these reports to humans’ safety, if any, has not been established,” said the FDA.
Not Worth The Hassle
The second major problem with antibacterial soaps, which we’re much more certain about, is that they generally aren’t worth their inflated sticker price.
In 2007, Aiello and her colleagues performed a review of the available research, including their own, and found that commercial antibacterial soaps weren’t any better than ordinary soap and water at preventing illness or reducing the amount of bacteria on people’s hands after washing. More recently, a September 2015 study that recruited volunteers to willingly rub bacteria onto their hands before washing with either type came to a similar conclusion.
While triclosan does have an antimicrobial effect, it’s likely that the brief amount of time most people spend on handwashing is simply too short for it to work its mojo. Similarly, the concentration of triclosan found in most antibacterial soaps, 0.3 percent, may also be too puny to do anything.
And really, that’s the biggest reason why scientists like Aiello have been wary about antibacterial soaps, at least for everyday consumer use. There’s no practical benefit for their use over conventional soaps, aside from a catchy-sounding label, meaning that any potential risks they carry are that much less acceptable. And though she would have preferred the FDA to have taken action against them sooner (the agency has debated the issue since at least 2005), she is happy about their pending decision.
“It’s something I’ve been passionate about for many years, thinking about whether these products should be out on the shelf.” she said. “It looks like things are changing finally. It would have been nice if it happened more rapidly, but it’s happening now, which I think is a good thing.”
Even as triclosan has steadily fallen out of flavor in recent years, though, there are already would-be imitators ready to take its place, particularly a group of chemicals called quaternary ammonium compounds that had mostly been used in surface cleaning products up until recently. There are similar worries about their growing popularity.
“There’s also some concern there, because those do leave residues, and they may also kill certain types of bacteria better than others, so they might change the microbial composition in the environment,” Aiello said. “I could see these ingredients fill the gap when triclosan leaves, but the problem is that we don’t yet have the research on these compounds, as much as we did with triclosan at least. We’re going to have to follow suit and do the research.”
Not all antimicrobial products are a marketing scam or potential health hazard, though. Alcohol-based hand sanitizers don’t have any of the problems that come with triclosan and likely don’t contribute to antibiotic resistance, a misconception that Aiello has often encountered. And antibacterial soaps are still a practical, even essential, tool in hospitals and other places where people with poorer immune systems spend lots of time.
Still, for those of us worried about germs in our homes or workplaces, it turns out there’s already an easy, risk-free way to better protect ourselves from them — we’re simply not taking enough advantage of it.
“Just for the general public, plain soap and water is very good at reducing pathogens on the hands. What you have to do is make sure is that you’re washing them properly,” Aiello said. “Most people, unfortunately, don’t rub their hands together long enough or dry them off properly. We need to be instilling those practices in the community.”
“Importantly, because washing with antibacterial soaps has not proven to confer a benefit when compared to washing with plain soap and water, the agency continues to recommend that consumers wash with plain soap and water to help avoid getting sick and prevent the spread of germs,” said the FDA.
Just how long should we wash our hands? Aiello suggests about the length of two birthday songs sung back-to-back. For the karaoke-inept, that’s about 20 seconds.
Source: Medical Daily
