The 5-Second Rule Actually Applies … But Only to Some Foods

Growing up Italian, there weren’t a lot of rules in the kitchen. Nonni was pretty lax about washing produce, didn’t care much about how round (or not) her meatballs were, and using precise measurements for pasta sauce? Nah, that wasn’t a thing. So I guess I shouldn’t have been surprised when, during one family dinner, I saw her drop an entire pile of fresh pasta on the ground, scoop it up, rinse it off, and serve it to our entire family a few minutes later.

Whether you’re squirming just thinking about food hitting the germy floor or nodding your head in approval, one thing’s certain—the “five-second rule” isn’t just a myth among middle-schoolers. In fact, this childhood rule is alive and well—so much so that researchers have spent some time studying it.

Turns out there’s more to the five-second rule than you thought. Here are the three factors affect whether the rule applies—and all the research-backed facts you need to know.

1. The texture of the surface it falls on

OK, so let’s say you’re making toast for breakfast. You’re just about to butter that fine piece of carbs and whoops—it hits the wood floor. Bad news: Foods dropped on smooth surfaces like wood, linoleum, and tile are up to 68 percent more likely to pick up nasty germs like salmonella that could be lurking therein. But if you drop that same piece of toast on carpet? Odds it will pick up bacteria drop significantly—there’s just a 0.5-percent chance bacteria will make its way onto the slice.

2. The type of food that hits the floor

Let’s be real—if a piece of broccoli drops to the floor it’s probably going straight in the trash. But drop a heavenly chocolate-chip cookie? Well, five-second rule obviously applies! Actually, your intuition might be spot on here: Whole foods are far more likely to attract bacteria than drier, processed foods. Researchers compared healthier foods like dried fruit to processed foods like white bread spread with a sugary jam, and noticed that after three seconds, the dried fruit had collected far more bacteria than the bread.

3. The length of time food stays on the floor

And finally, when does  this rule measure up to its name? You might have to move a little faster when you go to grab that slice of toast off the floor: Researchers found that food that hung out longer on the floor, around 30 seconds, was far more likely to carry bacteria and viruses than food that had been picked up within three seconds.

Of course, food that’s been contaminated with bacteria is always risky to eat, but the odds are if you already have a healthy immune system, you’ll probably be OK. Just in case, it might be best to pop a few probiotics to help fend off any nasty bacteria.

Moral of the story? If you’re going to eat off the floor, make sure it’s a relatively dry, processed snack that you drop onto carpet. And be quick—the longer you wait, the more bacteria!

Photo credit: Alicia Cho