WEDNESDAY, May 22, 2002 (HealthDayNews) -- Sweat stinks, right?
Not so: Body odor only becomes a problem when you toss in bacteria that thrive in the moist, dark environment of the armpit. However, you can stanch the stench by simply starving the bacteria of an essential element -- iron.
So says new research just presented at the annual meeting of the American Society for Microbiology in Salt Lake City.
Researchers with the Unilever Research & Development Laboratory in Port Sunlight, Great Britain, made their discovery after measuring levels of underarm bacteria and odor in 50 subjects over the course of two weeks.
They devised a process of making iron unavailable to underarm bacteria by binding it with certain molecules. This resulted in substantial decreases in the amount of bacteria that cause body odor, the researchers say.
On average, the use of a traditional, ethanol-based deodorant reduced the number of bacteria per square centimeter by anywhere from 70 percent to 90 percent in the study subjects. The addition of the iron-binding substance to the spray deodorant cut the amount of bacteria another tenfold.
The researchers prevented the iron from uniting with the bacteria by using two specific molecules -- one, diethylenetriaminepentaacetic acid (or DTPA); the other, butylated hydroxytoluene (BHT).
Binding the molecules with the iron doesn't kill the bacteria. It simply makes the iron inaccessible. Without the iron, the bacteria can't grow, study author Andrew Landa says.
"We observed that iron is essential for bacteria to live on your skin, and by reducing its availability, the bacteria simply can't thrive," he says.
By thwarting bacterial growth, the process sets itself apart from cleansers such as antibacterial soaps, which only kill bacteria, Landa adds. "Our process doesn't work to kill the bacteria, but instead interferes with their growth and division."
That's important, he says, because with traditional ethanol-based deodorants, the ethanol evaporates over a short period of time, letting more bacteria grow.
By blending the iron-depleting process with the deodorant, underarm bacteria gets a double-whammy -- first it's killed by the ethanol, then it can't grow back because it's deprived of iron, Landa says.
By reducing the amount of bacteria, there's a significant reduction in body odor, he says.
While the research is in its early stages, dermatologists say the best way to reduce body odor is still the old-fashioned way: through thorough washing -- both of your body and your clothes.
"I'll get many patients who are having trouble reducing body odor, and they'll say they wash under their arms every day," says Dr. Jerome Litt, an assistant professor of dermatology at Case Western Reserve University in Cleveland. "And then I'll ask them how often they wash their clothes."
"Often, they'll consider themselves to be relatively clean, but perhaps they'll wear a shirt two or three times before washing it again," he says. "And I have to explain the garment can harbor bacteria, so no matter how well you wash, the shirt -- or even a sweater -- is going to hold onto underarm odor unless you wash that, too."
Litt says he hasn't heard of any other research into iron's influence over body odor. However, he adds that antibacterial soaps work well.
"The soaps reduce the bacteria enough to eliminate odor," Litt says. "So if you wash your armpits every morning and use clothes that have been well-cleaned, then you shouldn't have deodorant problems."
What To Do: The University of Texas Southwestern Medical Center offers this informative site on body odor. If you have a teen, or are one yourself, here's a helpful site on Body Odor: 12 Ways to Feel Fresh and Clean.
