After only one week, unwashed pillowcases can harbor more germs than a toilet seat, according to a study

How Often Should You Change Your Pillows: Here's the Answer [Upd. 2021]

If you’re not in the habit of washing your sheets and pillowcases on a weekly basis, some eye-opening statistics might convince you to change your ways. Experts recommend washing bedding, including sheets and pillowcases, at least once a week for optimal freshness and hygiene—a piece of advice we should all take to heart.

A study conducted by mattress and bedding company Amerisleep revealed some shocking findings about the amount of bacteria that can accumulate on unwashed bedding. The study enlisted three volunteers who were instructed not to wash their sheets and pillowcases for four weeks. Swab samples were collected weekly and sent to a lab for testing—the results were nothing short of astonishing.

After just one week without washing, pillowcases were found to harbor an average of 3 million colony forming units (CFU) of bacteria per square inch, which is over 17,000 times more than a toilet seat. Sheets fared even worse, with 5 million CFU after one week—nearly 25,000 times more than a bathroom doorknob.

As each week passed without washing, the bacterial volume per square inch on both sheets and pillowcases continued to increase. After a month without laundry, pillowcases reached an average of nearly 12 million CFU (39 times more than a pet bowl, as per Amerisleep), while sheets accumulated about the same amount, but closer to 11 million CFU (5.4 times more than a toothbrush holder).

Are these germs actually dangerous?

The answer is both yes and no. The study identified four types of bacteria that were most commonly found on unwashed bedding, including both harmless and potentially harmful types. The most prevalent were gram-negative rods, which the CDC warns can potentially cause infection and contribute to antibiotic resistance. Bacilli, known for causing food poisoning, was another type of bacteria found on the bedding. However, there was also a significant presence of gram-positive bacteria, which are generally not known to be harmful.

Before you start panicking, it’s important to remember that bacteria is ubiquitous and present in our everyday environment. We come into contact with bacteria on various surfaces throughout the day (and some of them are beneficial to our health!). Nevertheless, it’s advisable to minimize unnecessary exposure to harmful bacteria whenever possible—and one way to do that is by taking control of your own bedding hygiene. The first step is to wash your sheets and pillowcases at least once a week.

Leave a Reply