Tuesday, December 11, 2007

Sham: Anti-Microbial Ingredient "Triclosan" a Dangerous Overkill

Ever run into one of those Howard Hughes-type people who are so afraid of bugs that they quiver before shaking hands, and then immediately reach into their pocket for a vial of antimicrobial hand sanitizer? Well, if not, you will sooner or later. More and more people are so concerned about "germs" that they want to spread these antimicrobial compounds all over their bodies and their living quarters.

Everywhere you turn, there are new "Anti-Bacterial" coatings on kitchen items and in an increasing variety of soaps, shampoos, and hand sanitizers. Many of these contain the ingredient Triclosan, once touted as a modern-day miracle to keep the bugs at bay.

But Saint Joseph’s University medical microbiology expert Michael McCann, Ph.D., says to think twice before reaching into your pocket for a tube of antimicrobial hand cream.

“The use of antimicrobials by the general public may be a literal case of over-kill,” notes McCann. “Research suggests wide-scale application of these sanitizers promotes the evolution of drug-resistant strains of bacteria. Many contain chemicals like triclosan that specifically kill bacteria, but do not harm us. The problem is, triclosan can trigger ‘selection.’”

McCann explains that selection occurs when conditions become favorable or unfavorable for individuals of the same species, based on genetic variation. In this case, if millions of bacteria are exposed to triclosan, it kills almost all of them. But if one of those bacteria has a genetic mutation that enables it to survive the lethal chemical, then the application of triclosan will select for that individual. Only bacteria resisting the chemical survive. Descendants of resistant bacteria also carry the mutation, which leads to the generation of large populations of resistant organisms.

I've found in reading about Triclosan that there are many opinions on this matter, a lot of them disagreeing with Prof. McCann. Still, I believe we must take McCann's point seriously. The problem of "selection" is exactly what happened with antibiotics, and why some strains of bacteria are no longer susceptible to many commonly used antibiotics.

Dr. McCann says studies have shown sanitizers that use alcohol (ethanol and/or isopropanol) are much more effective at killing microorganisms and inactivating viruses than Triclosan. Further, there does not seem to be a mechanism by which bacteria and other organisms can evolve resistance to alcohols. . . that's another reason to use these products.

So if you can’t get to soap and water quickly, it’s safe to break out the hand sanitizer, as long as it contains alcohol and not triclosan.


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