The five-second rule is actually legit, according to a new study by scientists who are laughing that they got research money to test this.
The “rule” goes, if you drop food on the floor, it's OK to still eat it as long as you pick it up within five seconds. That is actually pretty accurate, say researchers at Aston University's School of Life and Health Sciences in the U.K.
For the study, Anthony Hilton, a professor of microbiology, and his students tossed a variety of foods – toast, pasta, cookies and sticky candy – on the floor to see how much bacteria (E. coli and Staphylococcus) stuck to them. They tried it on various types of flooring – carpet, laminate and tile – for 3 to 30 seconds.
The longer the food sat on the floor, the more bacteria it accumulated. Carpeting was least likely to transfer bacteria, and tiled surfaces and laminate were most likely.
And, logically, the moister the food, the more likely it was to pick up bacteria.
However, Hilton warns people to remain cautious. “Consuming food dropped on the floor still carries an infection risk,” he says in a statement “as it very much depends on which bacteria are present on the floor at the time; 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 a myth.”
Eating fallen food is a common habit, apparently. The researchers found that of the people they polled, 87% ate food they'd dropped on the floor, and of those, 81% followed the five-second rule. A slight majority of the people who said they would eat dropped food were women (55%).
The researchers didn't address whether someone witnessing the food drop affected subsequent consumption. Or how the statistics might be affected if the dropped food was bacon. Or if the toast was buttered, and if it landed butter-side down. There was also no information on whether they used toddlers to throw the food items on the floor.
“Our study showed that a surprisingly large majority of people are happy to consume dropped food, with women the most likely to do so. But they are also more likely to follow the five-second rule, which our research has shown to be much more than an old wives' tale,” the researchers say.
However, if your dog licks the food within that five-second window, all bets are off.