It’s a bummer when you unwrap that miniature piece of chocolate only to have it drop on the floor. Who wouldn’t be tempted to eat it anyway, especially if it only landed on the ground for a few seconds; after all, there’s a “five-second rule, right?” But just because you’ve been hearing this notorious rule for years, it doesn’t mean you’re actually in the clear when it comes to avoiding germs and bacteria.
Unfortunately, just because popular folklore references this rule of thumb doesn’t actually make it true. In fact, research has found that no matter how quickly you pick up food that falls on the floor, you’re still going to pick up bacteria with it, even if it has been on the ground for five seconds or fewer.
“The ‘five-second rule’ is a popular myth that’s been around forever, but unfortunately no, it’s not a real rule we can follow,” says Arefa Cassoobhoy, MD, MPH, medical editor at WebMD. “Eating food that’s fallen to the ground does come with a risk of taking in bacteria known to cause food poisoning. Research shows food will instantaneously pick up bacteria from the surface it lands on.”
One study published in the journal Applied and Environmental Microbiology tested a variety of foods on a number of floor surfaces, and it found that no fallen food completely escaped contamination. However, the research did find that the longer the food was left on the floor, the more bacteria it contained, which could help explain how the five-second rule came about. Still, even if your food dropped for just a second, it still puts you at increased risk for food-borne illnesses.
Although how long the food remains on the ground does make a difference, it turns out the type of floor surface as well as the composition of the food matters even more. Surprisingly, carpeted floors transmit fewer bacteria than floors made of tile and stainless steel, according to the study. Wood floors, however, varied in how much bacteria they transmitted. As far as types of foods, wet foods such as watermelon have the highest rate of contamination, while drier foods—like that piece of chocolate— pick up fewer bacteria.
When you eat food off the ground, you’re putting yourself at risk for picking up bacteria such as E.coli and Salmonella, according to Berkeley Wellness. Both of these bacteria can cause some unpleasant side effects, and they can even sometimes be deadly. When dropping food, it’s important to use your best judgment. Did it fall somewhere that’s in a busy area? Do you clean there often? What type of food is it? And is it really worth saving?
“Bottom line, I’m not sure how likely you’ll get sick from eating food off the floor, but if it’s a moist food fallen in a high traffic area, like around my kitchen table, I can tell you, I’ll be throwing it away,” says Cassoobhoy. We’ve all done it once or twice before, but sometimes, you’re just better off safe than sorry. Don’t think you have time to properly clean your kitchen to avoid food borne illnesses? Check out these tips to clean your kitchen fast.