UK study shows that five-second rule exists

You've fixed yourself a snack. You're crossing over to the living room when a cracker slides off the plate and lands on the floor. Oh well, no problem. By the five-second rule, you can still pick it up right away and eat it, right? In recent years, the answer has been a resounding "no!"

Wait, though! Don't throw that cracker out just yet. A new study out of the UK has shown that there may be more to the five-second rule than we thought.

Anthony Hilton, a professor of microbiology at Aston University in Birmingham, UK conducted an experiment with his final year students, dropping different types of food — toast, pasta, biscuit (or cookie) and "a sticky sweet" — onto carpet, laminate floor and tile. They left the food there for between 3 and 30 seconds, and then tested for the transfer of two different common bacteria — E. coli and Staphylococcus aureus.

Their findings showed that the amount of time the food is in contact with the floor has a big effect on how much bacteria is picked up. Also, the lowest chance of picking up bacteria is for food dropped onto carpet, while the highest chance is for moist food dropped onto wood or tile and left there for longer than five seconds.

"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 in an Aston University press release. "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."

"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."

A survey conducted by the research group showed some interesting results too. Of those asked, 87 per cent said that they'd eaten food they dropped on the floor and they'd do so again. A little over half of those respondents were women, and over 80 per cent of them said that they'd follow the five-second rule.

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A surprising thing about the study, at least at first glance, was that carpet had the least chance of transferring bacteria. However, when you think about it, that makes some sense. As with the 'fist-bump' story from back in November, the amount of surface contact plays a big role in bacteria transfer. Wood and tile are very flat, so nearly the entire surface of the food would come into contact with the floor surface. For food dropped onto carpet, only the tips of the carpet pile would touch, with lots of air space in between.

Just as a caveat, though, before anyone goes and starts applying the five-second rule no matter where they are, take careful note of Hilton's comment about how there's still a risk of infection. The study showed that the chances of picking up bacteria are less with less time (and dependent on the surface), but it doesn't say anything about no bacteria being picked up. Also, you'd need to take the conditions of the floor into account too. Doing it at home, where you're reasonably sure of it being clean (or at least you being used to the bacteria in the environment), might be okay, but so doing it in a public place is probably not advisable.

(Images courtesy: Wikipedia, Getty)

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