Health

Here's What You Need To Know About The Five-Second Rule

WAIT. Before you eat that chip off the ground, read this.

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We all do it — don't even try to deny it.

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Drop a few French fries? A cookie? A freshly toasted bagel? As long as it's been on the ground for less than five seconds, then it's good — right?

The rule assumes that if food only touches the ground for a few seconds, it hasn't even picked up enough germs to be inedible.

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But...is that true? We reached out to germ expert, Dr. Charles Gerba, professor of microbiology at the University of Arizona, to find out if there's really a time limit on eating food off the floor.

Here's the thing: Food instantly picks up all the germs from the ground wherever it falls. So the rule is pretty much bogus.

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Germs don't wait. The second a piece of food makes contact with the floor, any germs on that spot will transfer to the food. Bacteria and viruses can't jump or move around, so it's not like they're slowly crawling onto a piece of food from the floor and increasing with every second.

"Countless studies have shown that food has the same amount of germs from the ground whether it's been five seconds or ten minutes," says Gerba.

Basically, the rule is more psychological than scientific.

What matters most is where you drop the food and what kind of bacteria or viruses are hanging out there.

If the ground is contaminated with a pathogen (germs that cause infection), food that touches the ground will get contaminated too. Obviously, this risk varies depending on the floor — a meatpacking plant is much worse than a bedroom. But carpets can be particularly grimy, since the bacteria there are harder to remove. And any high-traffic area is especially bad, since all sorts of stuff can be tracked around by people and animals.

Fun fact: Almost all indoor floors contain fecal organisms, Gerba says, which get tracked in on your shoes from the bathroom. So yeah, there's usually poop and diarrhea on the ground. And it can contain infectious bacteria like E. coli or salmonella if the poop comes from a sick person.

The stickier, wetter, or greasier the food is — the more germs it picks up.

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"Soft foods increase your risk because the texture allows the food to pick up more organisms," Gerba says. It's also just pretty disgusting if you can see visible pieces of dirt or hairs on that piece of cheese or those apple slices you pick up off the kitchen floor.

Hard or dry foods are safer to eat off the ground because they don't pick up nearly as much junk, Gerba says. But anything that is remotely wet or sticky is like a lint roller for floor bacteria.

The good news? Most germs on the ground probably won't make you sick.

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Most bacteria on the ground are from the environment or carried by humans — they could even be considered "good germs."

"Even if there is a pathogen, the food has to land on the right part of the floor and pick up the right organism to make you sick," says Gerba. The chances of this all lining up are relatively low. There's always a small risk there, says Gerba, because fecal organisms can spread disease. But don't panic — eating a chip off the kitchen floor probably wont send you to the ER.

Basically, when you eat food off the ground, you may as well be licking the bottom of your shoe, Gerba says.

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The comparison is gross, but this is probably the most logical way to think about the germs that get onto your food when it touches the ground.

"About 90% of shoes have fecal bacteria which survives on the bottom either from humans or pets and animals," says Gerba. Again, most of the time this stuff won't make you gravely ill but it's still an issue of hygiene and cleanliness.

"If you don't care and you're willing to take the risk, that's fine — but just be aware that it exists," Gerba says.

So the five-second rule is really more of an excuse to eat gross food that you should probably clean off or toss instead.

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Even if the floor is clean and you don't wear shoes in your home or wherever you dropped the food, you can't be sure it's germ-free, says Gerba. Bacteria is microscopic so you won't see it with the naked eye.

If you'd rather be safe or suspect your floor is gross, just throw away the food you dropped. Or if you drop something with a smooth surface like fruits or vegetables, just give it a good rinse in the sink, Gerba says. Otherwise, be careful.