Why You Shouldn't Follow the Five-Second Rule

How safe is the food you dropped on the floor for just a second? (Photo by Corbis)Santa Claus, the Tooth Fairy, the fact that your dad is stronger than every other kid's dad; These are all things you probably once believed in until you tragically found out they were, well, flat-out lies (unless, of course, you had one unusually fit dad).

And there's actually another myth to add to the list: the five-second rule.

Yep, turns out that your scooping up a piece of food from the floor within moments of dropping it will not keep it free of germs. If there are dangerous bacteria lurking on your floor, being lightning-quick in picking up that bagel that just slipped from your hands won't help.

"Does the contact time make a difference? No, that's a myth," Dr. Paul Dawson, a professor of food science at Clemson University, told Yahoo! Shine. 

Dawson and his team tested the five-second rule by purposely putting dangerous bacteria like salmonella on surfaces and placing different types of foods on them for various amounts of time. The outcome? Bacteria transferred immediately. Removing the food within five seconds simply didn't make a difference.

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And chances are that if you do drop something you plan on eating, you’re probably going to do it in the most germ-riddled room in the house: the kitchen. The concern "is cross contamination, which can come from foods that haven’t been washed and raw meat," said Dawson. "The more people who handle a food, the worse it is."

A high school senior named Jillian Clarke tested the rule during her internship at the University of Illinois at Urbana-Champaign in 2003. Perhaps her most interesting finding was the fact that after she swabbed a sampling of surfaces around campus, she found too few microorganisms to even conduct the study, Meredith Agle, the then doctoral candidate who supervised the study, later told WebMD. But after placing a measured amount of E. coli on sample surfaces and then putting cookies and gummy bears on said surfaces, Agle and Clarke (who was honored with something called the Ig Nobel prize) found that the germs indeed transferred in less than five seconds.

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Since then, similar research has been conducted at universities around the country. And just last year, researchers at Manchester Metropolitan University in the U.K. discovered that foods with a higher salt or sugar content ended up having a lower chance of hanging on to the harmful bacteria versus healthier foods with a higher water content, such as fruit. (Clumsy people could potentially take the news as justification to eat more junk food.)

So now that we know that food is contaminated by bacteria the moment it hits the ground (or any other surface for that matter, including kitchen counters, which can more germs than the floor, Dawson said), what kind of bad things can actually happen if you then eat that food?

Well, it depends. The worst culprits are strains of E.coli, salmonella, and the lesser known, but actually more common campylobacter, all of which can cause nasty symptoms like abdominal cramping, vomiting, and diarrhea, and in extreme cases lead to bigger issues including pneumonia, kidney failure, a compromised immune system, and even death. But Dawson insists those strains are pretty rare.

In other good news, the chances you’ll wind up sick from any of them are lower than they were 17 years ago. “The incidents of food-borne illnesses have declined since 1996, when the CDC started keeping track,” added Ruth Frechman, a registered dietician and spokesperson for the Academy of Nutrition and Dietetics. “There’s more awareness in general, more awareness to keep hot food hot, cold foods cold, to wash your hands.”

Dawson's biggest piece of advice? Though you probably won’t die or even get sick from the bacteria you ingest from food off the floor, you’re best off playing it safe and simply tossing anything you drop. “Eating food off the floor is kind of like not wearing a seat belt. Someone can go their whole life without wearing a seat belt and be fine until the day they get into an accident.”