Science has some bad news for five-second-rule believers.

By Hollee Actman Becker
September 20, 2016
five-second rule
Credit: Shutterstock

Uh-oh. According to a new study, the five-second rule—you know, the one that says you can eat food off the floor as long as you pick it up before you count to five—is completely bogus.

Bad news for my 10-year-old, who is literally plucking up fallen French fries from the family room hardwood and shoving them in his mouth as I sit here and type this.

According to professor Donald W. Schaffner, the food microbiologist at Rutgers who studied this phenomenon, no matter how fast you scoop up that food, you will also be scooping up a side of bacteria along with it.

Researchers dropped four different foods—cut watermelon, bread, buttered bread, and strawberry gummy candy—onto four different surfaces (stainless steel, ceramic tile, wood, and carpet) that had been treated with bacteria similar to salmonella. Then tested it after four different contact times, ranging from one to 300 seconds.

The results?

While longer contact times did, in fact, result in the transfer of more bacteria, no dropped food was completely free from contamination. "Bacteria can contaminate instantaneously," Schaffner explained.

Guess my kid better learn how to hold on a little more tightly. That being said, the food's composition and the surface it hit both also came into play. Carpet had a lower transmission rate than tile and stainless steel, for example, and watermelon with all its moisture, gathered more bacteria than a hard gummy candy.

"I will tell you on the record that I've eaten food off the floor," Schaffer confessed to The New York Times, then quickly added: "If I were to drop a piece of watermelon on my relatively clean kitchen floor, I'm telling you, man, it's going in the compost."

Words to live (and chew) by.

Hollee Actman Becker is a freelance writer, blogger, and a mom. Check out her website for more, and then follow her on Twitter at @holleewoodworld.