Five-Second Rule Put To The Test
March 15, 2014

The Five-Second Rule: Is It Scientifically Legitimate?

redOrbit Staff & Wire Reports - Your Universe Online

While skeptics may dismiss it as an excuse for people to not waste a fallen morsel of their favorite foods, new research from the Aston University microbiology professor Anthony Hilton suggests that the so-called “five second rule” might have some scientific merit.

According to CNET’s Chris Matyszczyk, Hilton instructed his students to drop toast, pasta, cookies, sticky candies and other types of food on a variety of surfaces (including carpet, laminate flooring and tiled surfaces), then after a period of between three and 30 seconds, they checked each item for E. coli and Staphylococcus aureus bacteria.

The students found that food is more likely to attract microbes the longer it remains on the floor, though the actual risk level varies by surface type. The transfer of bacteria was most likely transferred from laminate or tiled surfaces to moist foods that were on the floor for at least five seconds, but the least amount of microbes got on the food when it was dropped on a carpet, Jenn Harris of the Los Angeles Times reported on Friday.

In addition, Hilton conducted a survey of people regarding their “five-second rule” attitudes and behaviors, and found that 87 percent of those polled said they had or would eat food dropped on the floor. Of those individuals, 55 percent were women, and 81 percent of those females who said they would eat food off of the floor also said they would follow the five-second rule, the university said in a statement.

“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 5 second rule, which our research has shown to be much more than an old wives' tale,” the professor said. “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.”

“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; 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,” Hilton added.

However, you might not want to quickly pick up and munch on that dropped potato chip or chicken nugget just yet. As Contributor Alice G. Walton explains, you might want to take these findings “with a grain of salt,” as the study has not yet been peer reviewed or accepted for publication in a scientific journal.

“Whether scientists have really ‘proven’ the legitimacy of the five-second rule is debatable, so it’s fine to remain a little skeptical,” she added. “If you’re partial to the practice, use your best guess about the risks: If your food is covered with fuzz after three seconds on the floor, you may just want to move on.”