Health and Medicine
PUBLISHED
Most experts recommend washing bed sheets once a week, or every two weeks at a push, but more often if you’ve been sick recently or heavily sweating. If you think these claims are fussy overkill, read this before passing judgement.
Be warned, if you ever come across an online factoid saying something like “bed sheets are filthier than a toilet bowl,” then chances are, it probably originated with some PR from a bedding company looking to flog you new products, not a peer-reviewed study by benevolent microbiologists.
That's not to say, however, that your bed can't easily become a hive of microorganisms and other nasties if not washed a sufficient amount.
What lurks in your bed
The average person spends around a third of their life in a bed, either sleeping, attempting to sleep, or doing… other activities. Spending these prolonged periods wrapped up in a duvet allows a huge amount of sweat, bodily oils, and dead skin cells to build up on the sheets and pillowcases.
If you consider how often you wash your clothing, this should give you a bearing on the stanks, stains, and other unpleasantness that can quickly build up on fabric that's forced to be intimate with a human.
This is before we mention the bacteria, fungi, and other microbial lifeforms that can accumulate in your bed. If you sleep with cats or dogs, expect to add hair, dander, dirt, faecal matter, and an even more diverse range of microbes to the mix.
One of the most undesirable residents in hospital beds is Staphylococcus aureus, a ubiquitous bacterium that can cause skin infections, as well as E. coli, an equally ever-present bacterium associated with food poisoning and poop.
There’s surprisingly little scientific evidence on the microbiome of the average bed. However, some studies suggest our homes are filled with the same microbial communities that live on our skin, so it's reasonable to imagine they accumulate in the bed in even greater concentrations.
Interestingly, this domestic microbiome creates a “microbiological aura” that follows us around when we move house, in the words of a 2014 study.
How often do people clean their bed sheets? Not enough
You may be relieved to know that you’re not alone with the lax bed sheet cleaning routine. Alternatively, you might be dismayed to hear how filthy your fellow humans can be.
A 2022 poll by YouGov in the UK found that 28 percent of respondents washed their bed sheets weekly. The largest cohort (36 percent of people) was the one that washed their sheets every two weeks, while 9 percent washed them once every three weeks and 11 percent once every four weeks.
On the more extreme ends of the scale, around 4 percent said they will happily leave their bed sheets for two months or more, and 2 percent said they did it more than once a week.
So that's what people are doing, but do we actually know if there is an optimal frequency for keeping those sheets nice and crisp? As mentioned, the evidence is pretty sparse, but at least some researchers have tried to tackle the problem.
A 2013 study concluded that, at least when it comes to controlling dust mites, a weekly washing schedule is recommended. More recently, a small study found that the quantity of microorganisms in bed linen rises rapidly in the first week, but then stays pretty stable.
None of this is quite conclusive, but it would seem those 28 percent of people on a once-per-week schedule are operating by a sensible rule of thumb.
Oh, and change your pillow too.
This is also a public service announcement that you should change your pillows every few years.
A 2005 study collected samples from 10 pillows that had been used for 1.2 to up to 20 years, concluding the long-lived pillows harbored a “substantial load” of many species of fungi, namely Aspergillus fumigatus, Aureobasidium pullulans, and Rhodotorula mucilaginosa.
Since we spend so much time with our faces pressed against a pillow, the research concluded that these fungi could be having an impact on people’s respiratory health, especially those with asthma.
