Science Says Stop Washing Your Jeans So Often

A college student wore the same jeans for over a year to test out a theory.

What would you do for science? We’ve heard about some pretty crazy stunts recently, like Norwegian scientist Andreas Wahl shooting himself with a bullet underwater to show that it was safe, but scientists using themselves as test subjects is nothing new.

Back in 2009, Josh Le, a student at the University of Alberta in Canada, decided to wear a pair of jeans for 15 months to see if he could put an end to the debate about how often you should wash your jeans. According to The National Post, he wore them every single day — even slept in them for a month — and did his best to “push it to the extreme.” If he spilled food on them, he simply wiped it off with paper towel.

SEE ALSO: How Your Jeans Could Help Clean the Air

When he finally took them off, assistant human ecology professor Rachel McQueen swabbed them for bacteria. Le then washed the jeans and wore them for another 13 days before swabbing them again. Interestingly enough, the bacteria levels were almost the same.

“I was pleasantly surprised. What I found was just normal skin flora. The counts were really, really similar. The bacteria load from the swabbed areas were pretty much the same,” McQueen told The National Post.

One of the techniques Le used to help with the smell was putting his jeans in the freezer once every couple of weeks, as recommended by Levi’s. However, scientist Stephen Craig Cary told The Smithsonian, that freezing your jeans to kill bacteria is a complete myth.

“One might think that if the temperature drops well below the human body temperature they will not survive,” Cary said, “but actually many will. Many are preadapted to survive low temperatures.”

Is it safe to rarely wash your jeans? In conversation with Business Insider, McQueen said it is — the bacteria that end up on our jeans mostly come from our own body, but "skin microorganisms are generally not hazardous to ourselves."

Of course Le and McQueen’s experiment was just one “study” done with a single pair of jeans. But, if you’re washing your jeans every week or so, you could probably change that to once a month. It would help save both water and electricity. Many jean brands also recommend not washing them for as long as possible so as to preserve the color and feel.