You’re at home, enjoying one of your favorite desserts while chatting with the family. However, in the course of having a conversation, you accidentally (and tragically) drop it on your kitchen floor. What do you do next?
If you’re like many people, you evoke the “5-Second Rule” and quickly pick up your snack (and maybe inspect it or brush it off a bit) so you can resume eating it. As a follower of this rule, you believe that if you pick up fallen food within five seconds, you can avoid it getting contaminated.
But does the 5-Second Rule actually have any merit? Believe it or not, science has something to say about it—and it doesn’t look good for those quick pick-me-ups.
To start, let’s look at the facts about foodborne illness. According to 2011 Centers for Disease Control and Prevention estimates, 48 million Americans get sick from foodborne illness every year—that’s 1 in 6 of us. Worse, 128,000 get so sick that they need to be hospitalized, and 3,000 die annually. It’s a serious health problem.
That’s why there’s interest in this 5-second theory. Since many people adhere to it, researchers have studied it to determine its effectiveness. For example, a 2014 study done at England’s Aston University seems to back the 5-second rule. Researchers found that, indeed, the sooner food was picked up, the less bacteria there was. Where it fell also factored into the amount of bacteria, with carpet (surprisingly) being the cleanest place to drop food.
However, that study (which still needs further review by the scientific community) seems to be an anomaly, as its results are contrary to what most other research says. For example, a study by San Diego State University (and funded by Clorox) showed that, regardless of surface, bacteria were found on the baby carrots and sippy cups they dropped within five seconds. More were concentrated, though, in certain areas: countertops for the carrots, and highchair trays for the sippy cup.
Likewise, a 2012 study done at Manchester Metropolitan University found germs on various foods within 5 seconds—but the amounts depended on the food type: salty or sugary foods, and foods with little water (bacteria feeding ground) contracted less bacteria.
So, the time period is not the only thing that determines how bacteria-filled your fallen food gets, but rather other factors such as what you drop and where you drop it. So take a second look at the 5-Second Rule. And remember that, regardless of circumstance, you can rest assured that dropped food will pick up bacteria—so the best course of action, especially if you have illness-prone young children at home, is to just dump the food that gets dropped.