Germaphobes, look away.
Uh-oh! You dropped that french fry on the floor. Five-second rule, right? According to the BBC, five seconds is five seconds too long if you want to keep your food from picking up dirt. Your fry was contaminated the instant it touched the ground—but that doesn’t mean it’s unfit for eating.
When food hits the floor it is immediately covered in microbes, but, for the most part, they’re harmless—and they’re not just on the floor. “You can’t hide yourself from microorganisms,” microbial ecologist Jack Gilbert told the BBC. “You are literally living and breathing a sea of bacteria.” And, yet, most of us aren’t constantly ill. “We are so paranoid about dirt and yet we have no comprehension of the pure luck—or bad luck—that it takes to actually pick up a pathogen,” Gilbert says. He even went as far as to say you could probably lick your toilet seat and not get sick. (We’ll just take his word on that.)
In fact, exposure to microbes is good for us. “If there are microbes on that piece of food it could contribute to the development of the healthy immune system,” biological anthropologist Katherine Amato says.
The only time you should truly worry about food or toilet seat contamination is if you are in the company of someone that is sick or somewhere known for poor hygiene. “If I dropped [food] into a plague pit, no, I wouldn’t pick it up,” says Gilbert.
So the truth about the five-second rule? It really doesn’t apply ever. If you’re somewhere relatively clean, go ahead and eat the fallen food whenever (well, within a reasonable amount of time). If you’re living through a pandemic, just let it go.