Many people dream of a world where their gym socks don’t stink, and pancake-sized pit stains don’t soak their shirt sleeves. The textile industry has tried to make that dream come true in recent years with a catalog of sleek, high-performance active wear – much of it designed with synthetics to sop up the sweat and stench.
So-called “anti-odor wear” makes customers feel fresh, but it may pose a health risk more vile than any gym odor, experts warn. A spate of recent studies suggests that consumers should think twice about treated gym clothes, especially those with antibacterial qualities, when searching for new garments this fall.
The biggest concerns surround antimicrobial clothes, which can contain germ-killing chemical agents such as triclosan and trichlorocarban. Increasingly, fitness products contain silver, a natural combatant of odor-causing bacteria.
Dr. Francine Yep, a family medicine practitioner with Sutter East Bay Medical Foundation, suggests that encasing our bodies in this type of clothing could wear down our microbiome – a community of bacteria that promotes nutrition, immunity and organ development – to an undesirable degree.
“We are learning more about how helpful germs keep our bodies happy and the environment healthy, too,” she said. “We don’t want to knock off the good guys.”
Silver breaks down the cell walls of microbes and interferes with their normal metabolic processes. Manufacturers get it into clothing by embedding small bits of silver into thread, or applying a topical liquid silver solution to absorbent fabrics. Reducing a garment’s microbe population can help curtail the pungent odor that arises when our sweat mixes with the naturally occurring bacteria on our skin.
Innovation Textiles, a United Kingdom-based trade publication, highlighted silver antimicrobial treatments in a blog post this spring, calling them the key to a new era: “odor control 2.0.” Silver-based technologies made up 9 percent of the anti-odor textile market in 2004, but have since grown to occupy more than a quarter of that category, the post said.
The appeal is twofold – smelling better is nice, and it also means fewer cycles in the laundry, said Kyle McClure, president of product development for Rhone Apparel. The New York-based company makes compression shorts, tank tops and T-shirts using silver-threaded yarn; they’re sold in major retail stores.
“It’s really about the recovery,” he said. “You can sweat as hard as you possibly can in it. You can wear it for a few days, and you will have a much fresher odor profile than if you were wearing normal polyester.”
When asked about the health risks of depleting the skin’s bacterial layer, McClure said it’s something to be aware of, but it hasn’t been shown to be a serious threat.
“The good thing is that nobody eats their T-shirts, so it’s not going to interfere with the gut bacteria that’s critical to human health,” he said.
Dr. Gang Sun, a professor of materials science at UC Davis, said these chemicals are worth worrying about. His research group is experimenting with a colored dye that would absorb ultraviolet light to reduce microbes on clothing.
Several environmental groups have also called out antibacterial clothing’s effects on water supplies. Researchers with the Swedish Chemical Agency found that 50 percent of silver, as well as antibacterial chemicals such as triclosan and trichlorocarban that are commonly used in active wear, rinse out after 10 rounds of washing, ultimately entering the water source.
Fleet Feet Sacramento, midtown’s hub for elite and amateur athletes alike, does not sell any antimicrobial products, and tries to market as many natural materials as possible, said apparel buyer Annette Scarlato. The store’s anti-odor line includes garments made of wool and bamboo fibers, both of which naturally absorb smell without actually killing germs.
“Knowing about those concerns, it doesn’t mean you’re not going to have new technology,” Sun said. “People still would like to have this anti-odor and antimicrobial function on the textiles. The goal is for us to have it with less negative impact to humans and the environment and a more beneficial design.”