How Often Should You Wash Your Sheets? A Microbiologist Answers

Fagjun | Published 2017-12-10 07:33
WTF

Philip Tierno, a microbiologist at New York University, weighs in on how often we should be putting our bed sheets in the wash. Hint: you’re probably not doing it often enough.


How do we keep too many bacteria and fungi on our sheets?

How do we keep too many bacteria and fungi on our sheets?

 

 

Anyone who has ever had to leave home for college may have experienced forgetting the last time they washed their sheets. We know that our sheets get dirty, but just how much may not be something we like talking--or thinking--about. Still, it’s a matter of personal health. If you keep your sheets for too long, you’re opening yourself up to a whole lot of microbes that can make you sick.

 

We spend about a third of our life in bed--maybe even more for some people. Thus, it’s important to keep our bed hygienic. Our sheets are teeming with microbial life--some of which are ours, but we also apparently share our beds with foreign bacteria and fungi. So how many times should we wash our sheets to avoid the harmful buildup of microbes?



A Nightmare Cocktail of Microbes


Microbes can give you allergy-like symptoms even when you don't have allergies.

Microbes can give you allergy-like symptoms even when you don't have allergies.

 

 

According to Tierno, the answer is once a week. Even if our sheets don’t get visibly dirty, they actual harbor a lot of tiny little critters that aren’t good for us. These microbes gather in the wrinkles and folds of our sheets, and they can cause certain illnesses if we’re not careful.

 

Humans shed fungi and bacteria that come from our sweat, dead skin cells, and vaginal and anal excretions. We produce about 26 gallons of sweat a year, and if you somewhere hot and humid, there are more chances for fungi to grow.

 

Our own microbes aren’t the only that we have to contend with. There are also dust mites, pollen, soil, lint, and animal dander. According to Tierno, all of the above can build up to potentially harmful levels in the space of just a week. He says that even if you don’t have allergies, an allergic reaction is possible since the microbes are so close to your mouth and nose when you’re in bed. These microbes can also increase your chances of developing conditions like asthma, eczema, and hay fever.

 

And it’s also not just the sheets. Mattresses can also harbor bacteria, and these bacteria can grow in number as the mattress grow older.



Changing Your Sheets


Keeping your bed clean can be a pain, but it's worth it.

Keeping your bed clean can be a pain, but it's worth it.

 

 

Older mattresses have higher concentrations of staphylococcus, enterococcus, norovirus and MRSA. It’s recommended that you replace your mattress every seven years, and you can also vacuum it and air it out regularly to keep too many microbes from growing.

 

If there are a lot of microbes on your sheets, does that mean that you’re unhygienic? Not really. "Just like Rome overtime was buried with the debris that falls from gravity, gravity is what brings all that material into your mattress," Tierno says. Thus, you can take a shower twice a day but you’ll still need to put new sheets on your bed every week.

 

So when was the last time you washed your sheets and put new ones on your bed? You don’t have to tell anyone exactly when, but if the answer isn’t “sometime within the last few days”, then you might want to put new sheets on now.

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