A new study from Aston University in England found that picking up food immediately after it falls on the floor decreases chances of the food being contaminated with disease-causing germs, giving scientific credibility to the "five-second rule."
A team of biology students led by microbiology professor Anthony Hilton tested how long it takes the bacteria E. coli and Staphylococcus aureus to transfer onto food when it stayed on the floor for a period of three to 30 seconds. The team dropped pasta, toast, a biscuit and sticky candy during the experiment. Researchers dropped the food on different types of floors, including laminate, tiled and carpeted floors.
"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 the time," Hilton said according to a news release from the university. "However, the findings of this study will bring some light relief to those who have been employing the five-second rule for years, despite a general consensus that it is purely myth."
The five second rule suggests that a piece of food is safe to eat as long as it is picked up within five seconds of it falling on the floor. The team found that not only did quickly picking the food up shorten the amount of bacteria, the amount also depended on the type of floor.
"We have found evidence that transfer from indoor flooring surfaces is incredibly poor with carpet actually posing the lowest risk of bacterial transfer onto dropped food," the news release said.
Bacteria were most likely to transfer to moist food if it was dropped onto tiled and laminated floors for more than five seconds.
The team also took a survey and asked students if they use the five second rule. Almost 90 percent said they would eat food after it falls on the floor, or did it before.
"Our study showed that a surprisingly large majority of people are happy to consume dropped food, with women the most likely to do so," Hilton said. "But they are also more likely to follow the 5 second rule, which our research has shown to be much more than an old wives tale."