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One in Four People Contaminate Their Food When Cooking With This Ingredient, New Study Shows

And how you can avoid it.
FACT CHECKED BY Mura Dominko

An integral part of menus and grocery shopping lists the world over, chicken is prepared and enjoyed by millions each and every day. Whether it's wrapped in a tortilla, nestled on a bun, or dipped in BBQ sauce, chicken is a staple of countless diets.

Freshly roasted chicken may be delicious, but anyone who's ever spent time in the kitchen knows that raw chicken is quite unappetizing. It's slimy, smelly, and quite literally covered in bacteria. Many people assume they should wash off raw chicken before cooking it—but that's a big mistake!

That's right: The consensus among experts, from the USDA to The Cleveland Clinic, is that there's no real need to wash raw chicken. All the potentially harmful bacteria, like salmonella, is killed when the chicken is cooked at a high temperature (at least 175 degrees Fahrenheit). In fact, washing your raw chicken can actually spread bacteria all over your sink, kitchen counter, and any nearby kitchenware or other foods.

New research conducted at North Carolina State University, and published in the Journal of Food Protection, set out to better educate participants on the dangers of washing raw chicken. Additionally, researchers also wanted to get a better grasp on just how easy it is to contaminate a kitchen when handling raw chicken. What their investigation discovered is shocking.

One in four salads contaminated

washing raw chicken
Shutterstock

Hundreds of home cooks participated in this study, with about half being explicitly told at the start that it isn't a good idea to wash raw chicken. The other participants, deemed the control group, were given no advice on how to prepare their meals.

Across both groups participants were asked to prepare a simple dinner consisting of chicken and a salad. To even the research team's surprise, roughly 25% of all salads prepared showed signs of bacterial contamination—even many salads prepared by subjects who did not wash their chicken.

What does this tell us? Merely avoiding the washing of raw chicken doesn't appear to be enough to keep a kitchen environment sterile. Study authors conclude that their findings emphasize the equal importance of hand-washing and immediate kitchen cleaning and sanitization whenever raw chicken is being handled at all.

Covert contamination

All in all, the study suggests it's super easy to transfer the bacteria from raw chicken to other foods. If your hand so much as grazes a piece of raw chicken, it's a good idea to wash up before doing anything else.

"We think the salad contamination stems from people doing a poor job of washing their hands after handling the raw chicken, and/or doing a poor job of sanitizing the sink and surrounding surfaces before rinsing or handling the salad," says corresponding study author Ellen Shumaker, an extension associate at North Carolina State University, in a university release.

Similarly, even sinks that weren't used to wash off raw chicken showed undeniable signs of bacterial infection.

"Regardless of whether people washed their chicken, the kitchen sinks became contaminated by the raw chicken, while there was relatively little contamination of nearby counters," Shumaker explains. "This was a little surprising, since the conventional wisdom had been that the risk associated with washing chicken was because water would splash off of the chicken and contaminate surrounding surfaces. Instead, the sink itself was becoming contaminated, even when the chicken wasn't being washed."

The experiment

This study featured 300 participants, all of whom reported regularly cooking at home. Importantly, all subjects also told researchers they usually wash off raw chicken. As touched on earlier, about half (142) were sent a "food safety information" document explicitly laying out the dangers of washing raw chicken. The others (158) were provided with no food preparation guidance whatsoever.

Next, each participant was invited to a controlled kitchen environment and told to cook a meal. Video cameras tracked each person as they prepared their food. More specifically, subjects were instructed to cook chicken thighs in an oven and then make a salad.

Just as each subject was about to put their chicken in the oven, researchers interrupted and asked to hold a quick interview. After chatting, participants were allowed back into the kitchen to finish cooking, eat, and then clean up as they normally would at home.

Crucially, study authors had inoculated each raw chicken thigh with a harmless but detectable strain of bacteria. This made it easy for the team to swab kitchen surfaces and assess salad samples for signs of cross-contamination.

Not washing isn't enough

Most people (93%) who were given the food safety information heeded the advice and didn't wash their chicken. Meanwhile, only 39% of the control group avoided washing their raw chicken.

While it's good news that most people made the correct decision when presented with the right advice, the results indicate not washing raw chicken is just one aspect of avoiding cross-contamination. Diligent hand washing and surface/sink sanitization is vital as well.

"Washing the chicken is still not a good idea, but this study demonstrates the need to focus on preventing contamination of sinks and emphasizing the importance of hand-washing and cleaning and sanitizing surfaces," Shumaker concludes.

John Anderer
John Anderer is a writer who specializes in science, health, and lifestyle topics. Read more
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