“Five Second Rule” May Be Real, Because Science
Go ahead, eat that cookie, toast, or even a wet hunk of steak right of the floor. According to a new study, food may have a very low chance of being contaminated after touching the floor, giving some credence to the so-called Five Second Rule.
Students at Aston University in Birmingham, England tested dry and wet foods on tile, laminate, and carpeted floors for the common bacteria E. coli and Staphylococcus aureus. They found that bacterial transfer was immediate upon contact, but that the foods picked up much less bacteria in three seconds than in 30 seconds on the tile and laminate floors. On the carpet, the food was still relatively bacteria-free even after the longer wait, and even for wet foods.
The findings are very similar to a Clemson University study in 2007, but the researchers reached different conclusions. Aston researcher Dr. Anthony Hilton said that the bacteria found was insufficient to contaminate the food; but Clemson Prof. Paul Dawson, responding to the new study, said it was enough to potentially sicken a human.
A video from Smithsonian.com on the subject also comes down on the side of caution. Molecular biologist Eric Schulze tells viewers, ”Eating food off the floor is a bit like playing Russian roulette with your gut… We track harmful agents like fecal bacteria on the soles of our shoes all the time. So no floor surface is guaranteed to be a safe bet.”