Dead skin, dust mites and semen: Aussie Tik Tok star Dr Karl delves into your sheets ‘yuck factor’

Ask your friends and family how often they wash their sheets, and it’s likely you won’t get a definitive or, in the case of some people – honest – answer.

Should you be laundering your bedding once week? Once a month? If you’re like one of half the single men in Britain who participated in this YouGov survey last year, maybe you haven’t changed your sheets for four months.

Even worse, you could be in the company of the four per cent of Brits who admitted their bedding sees the inside of a washing machine only once a year.

According to beloved Aussie science expert Dr Karl Kruszelnicki, it does depend on your lifestyle factors – where you live, whether you have pets, if you shower before you go to bed. But, as a general rule of thumb, you should be aiming for once a fortnight.

“On one hand, [wash them] enough so you don’t get bad reactions, like coughing, or skin infections, or bed bugs and so forth,” he told news.com.au’s podcast I’ve Got News For You.

@drkarl

How often are you washing your sheets? Science says probably not enough! #drkarlkruszelnicki #drkarl #science

♬ original sound - Dr Karl

“The average recommendation is that you wash them at least once every two weeks, because each day you shed about 1.5 grams of dead skin, and that 1.5 grams can attract and feed a million dust mites.

“And in addition to the dead skin cells, there’s sweat and germs and body oils and pollen and allergens … So it varies a lot depending on your environment.”

If you live somewhere “hot and humid” – like Queensland – Dr Karl suggested you might want to aim for once a week, though “maybe more, depending on whether you’ve washed before you go to bed”.

It also “makes sense” to wash them more frequently “if you’re prone to allergies, or asthma, or you sweat a lot … if you’ve got animals that jump on the bed, even little children, than there’s that yuck factor”.

He also revealed – in a titbit that will ruin hotel stays forevermore – that “semen stains on white cotton sheets can survive six trips through the industrial-grade washing machine system in a hotel and still provide a full genetic profile of the owner of that sperm”.

For those at home, “when you wash your sheets … leave room in the washing machine for the water [to] run through”, Dr Karl advised.

And don’t feel obliged to make your bed every day: “If you [don’t] make your bed, the sheets, they get a chance to air and equilibrate whatever chemicals happened to be on them with the air in the bedroom. So it does look a bit messy, but you’ve had a chance to dry”.