Not washing your jeans enough? There could be nasty consequences...

To wash or not wash your jeans? The debate rages, but we let actual scientists answer the question once and for all

couple doing laundry
(Image credit: Getty/Richard Drury)

Yesterday we reported that Stella McCartney isn't keen on washing clothes – in particular her bras, despite being a world renowned fashion designer. Fascinated? And Marie Kondo seems to have got half the nation obsessed with folding clothes the KonMari way

All well and good, but it has left us somewhat confused about how often we should be doing laundry. Washing jeans, in particular, continues to be a raging controversy. How often do you wash yours? Once every three wears? Every other week? Or... never? 

It all began with the CEO of Levis advising people to never wash their jeans in order to preserve their quality. According to the denim manufacturer (and inventor), all you need to do is pop your jeans in the freezer every once in a while in order to kill the bacteria that have accumulated on them. Human bodies shed tens of thousands of bacteria every day, so that's a lot of germs we're talking about that need to be frozen out.

Depending on where you look online, you'll find opinions both for and against this method of disinfecting your jeans, as well as many websites quoting 'a doctor' who tells them that human skin is 'resilient' and can take a bit of germ warfare.  

Does any of this advice stand up to scientific scrutiny? The short answer is 'no'. In an article by the Smithsonian, two scientists, experts on bacteria and skin microbiome respectively, have disputed the claim that freezing our jeans is enough to get them clean. The gist of their argument is that freezing will never kill all the bacteria on your jeans, as some can survive very low temperatures, and that it's more important to physically remove dead skin cells from the fabric, rather than attempting to exterminate bacteria. It's the dead skin and dirt that become a breeding ground for infection. Among the many nasty consequences of not washing your jeans could be acne and fungal infections, including in your, err, more delicate body areas. 

The good news for those who really don't like washing their jeans too often is that the mechanical process of removing dirt with warm water regularly will make them safe to wear, even if you do leave it a couple of weeks, rather than days, between washes. Just stop putting them in your freezer, please.