Are Anti-Bacterial Soaps Worth It?

With all the concern about MRSA and bird flu—not to mention a desire to avoid the common cold and intestinal complaints—it’s tempting to reach for the soap labeled "antibacterial" the next time you hit the supermarket shelves. In fact, data from the market research company Mintel suggests that that's exactly what Americans are doing: Sales of antibacterial hand soaps and antiseptic hand gels have been soaring in recent years.

However, a review of 27 studies on antibacterial hand soaps that was published in Clinical Infectious Diseases in September concluded that consumer soaps containing the anti-bacterial ingredient triclosan are no more effective than plain soap and water when it comes to removing bacteria from the hands or slowing the spread of disease.

In laboratory studies, most people who washed their hands with triclosan-based hand soaps had no fewer bacteria on their hands than people who washed with plain soap and water. In addition, longer-term studies of household use found that households that used antibacterial hand soaps had just as many instances of colds, flus, skin infections, and gastrointestinal problems as households that just used plain soap and water.

Allison Aiello, an assistant professor of epidemiology at the University of Michigan School of Public Health, was one of the lead researchers in this comprehensive review.  She stresses that in the few studies she reviewed where triclosan-based hand soaps were shown to have any benefit over plain soap and water, the concentration of triclosan was between 1 percent and 2 percent, concentrations that are significantly higher than the 0.1 percent to 0.45 percent found in most consumer products.

Aiello’s group didn't just conclude that there was no benefit to choosing triclosan-based hand soaps over plain soap—they also raised questions about the possible risks of including triclosan in consumer products.  Their biggest concern: the widespread use of triclosan in consumer products could lead to antibiotic-resistant bacteria.

To be sure, the concern is controversial.  To date, no one has shown convincing evidence that this is, in fact, happening in the real world.  However, Aiello stresses the difficulty of demonstrating cause and effect outside of the laboratory where so many variables and possible sources of antibiotic exposure are at play.

Also, Aiello points to laboratory research that has shown how exposure to triclosan can enable bacteria to evolve resistance mechanisms, as well as how those resistant mechanisms could be spread to other species of bacteria, leading to cross-resistance with antibiotics for treating serious infections.

Most importantly, Aiello stresses, "There are too few community-based studies to make a definitive conclusion about the potential risks to humans. Although we don't have conclusive proof that triclosan is contributing to antibiotic resistance in the community, that doesn't mean there isn't a reason to be concerned.  And since there is no evidence that triclosan-based hand soaps are more effective than plain soap for everyday consumers, why take the risk?"

Indeed, even hospitals in the U.S. are concluding that the risk isn't worth it.  For instance, at the University of Washington Medical Center, doesn’t use triclosan-based hand soaps due to concerns about the possibility of antibiotic-resistant strains of bacteria evolving. Instead, they rely on alcohol-based hand gels and hand soaps containing chlorhexadine gluconate, (CHG), a practice that’s consistent with CDC guidelines.

“So far, alcohol and CHG don’t seem to have any issues with antibiotic resistance,” says Robin Olsen-Scribner, infection control and health care epidemiologist at UW Medical Center.

In fact, Aiello points out that broad-spectrum antiseptics like alcohol kill bacteria in a completely different way than triclosan does. Since alcohol kills bacteria by physically rupturing the cell wall and many other components, it’s almost impossible for bacteria to evolve resistance.

What's a concerned consumer to do?

Most experts, including spokespeople for the CDC, agree that the best way to prevent the transmission of disease is to simply practice proper hand-washing techniques with plain and soap and water.  This means washing with soap and warm water for at least 20 seconds and drying with a towel to further aid in removing bacteria.

If water is not available, try an alcohol-based hand gel.  If used properly, these can be at least as effective as hand-washing in destroying bacteria and viruses.  Olsen-Scribner gives this advice for maximizing the effectiveness of alcohol-based hand gels:

• The hands must not be visibly soiled; otherwise, the alcohol-based hand gel won't work as well.
• The hand gel must contain between 60 and 70 percent alcohol. (Look for one that also contains a moisturizer, since alcohol can be very drying to the hands.)
• It takes the alcohol about 15 to 20 seconds to rupture the bacteria’s cell wall.  Therefore, you must use enough of the gel that it takes at least 15 to 20 seconds of rubbing to dry; otherwise, it won't be as effective.

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Lisa Farino is a Seattle-based health and science writer and a board member of the Northwest Science Writers Association. She is a regular contributor to MSN Health & Fitness.