It's not all that unusual for someone to drop a piece of food, claim "five seconds" and then pick it right back up and eat it. A microbiologist decided to test to see how true the silly urban myth is and found that that amount of time might be just right, in regards to the transfer of bacteria.
The study was done at the Aston University by Microbiology professor Athony Hilton and some final year Biology students, according to a news release. They put together a test where they dropped food from between 3 and 30 seconds and examined how much common bacteria, like Escherichia coli and Staphylococcus aureus transfers onto the food in that time.
The experiment, tested using various foods like toast, pasta and others, found that the surface also determined how long food was still reasonably acceptable to eat. "Consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at time," Hilton said. "However the findings of this study will bring some light relief for those who have been employing the five-second rule for years."
The study found that food dropped on carpet actually offering the lowest chance of bacteria transferring to food than laminate or even tiled surfaces. Unsurprisingly, the longer a bit of food is on the ground, the better a chance it has at bacteria transfer, especially if the food is moist.
Hilton and students also took a survey about the 5-second rule and found that 87 percent surveyed have or would eat food dropped on the floor and 55 percent of that number were women.