Your pillowcase may be harboring dangerous bacteria, a new study says.Photo:Getty Images

Sleepy girl trying to hiding under the pillow on bed.

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Sweet dreams are made of…this?

That number, the study says, means that “pillowcases washed a week ago have over 17 thousand times the number of bacteria as a toilet seat.”

Pneumonia-causing bacteria can be found on pillowcases that have been recently washed, a new study says.Getty Images

Bacteria

Sheets fared even worse after a week, racking up nearly 25 thousand times the bacteria that’s found on the average bathroom door knob.

And these bacteria, the study found, included the kinds that cause infections like pneumonia — as well as gram-negative rods, which “are dangerousand can lead to antibiotic resistance, according to the CDC.”

Bacilli — the type of bacteria that usuallycauses food poisoning— were also found on the bedding.

But there is a way to keep your pillowcase, well, cleaner than a toilet seat. While most guidance suggests that washing your bedding once a week is sufficient, it’s likely not enough, Mary Gagliardi, Clorox’s in-house scientist and cleaning expert, toldMartha Stewart.

“Some people may want to wash their pillowcases that they sleep on more frequently if they sweat while sleeping, have oily hair or skin, or go to bed with makeup on,” she said. “Eight hours times seven days equals 56 hours of use — even if you don’t sweat or have oily hair, that’s enough ‘wear’ to necessitate washing them with the rest of the sheets.”

And while the Amerisleep study didn’t note how different types of fabric might impact bacteria growth, Gagliardi pointed out, “Satin sheets need to be washed just as frequently as cotton percale or cotton flannel sheets.”

Washing your bedding more than once a week can help curb the growth of bacteria.Getty Images

Woman’s hand loading dirty blue bed sheets in a white washing machine

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And she cautions, don’t be too delicate with your bedding.  “People often reach out for advice on pillowcases that just won’t get clean, and it turns out they are washing in cold water and not using the appropriate bleach along with their detergent,” she toldMartha Stewart.

“Pillowcases need to be cleaned very thoroughly, so using hot water, a heavy-duty cycle for longer agitation, a good detergent with enzymes, and the appropriate bleach for the fabric and color will make a huge difference.”

And while washing your pillowcases regularly is an important part of limiting bacteria growth, at some point you’ll need to replace your pillows,Amerisleep says, because bacteria aren’t the only uninvited guests in your bed.

The company recommendsreplacing your pillowsevery 1-2 years. In the meantime, adding another load of laundry to your weekly chore list can help keep your bedding cleaner than your bathroom.

source: people.com