The five-second rule has been around for many years. According to age-old adage it is okay to pick up food that has touched the ground, as long as it is done within that time frame. But is it really? Depends on which scientific study you want to believe.
The two studies, one conducted in 2007 by Clemson University in South Carolina and the most recent one, by students and faculty at Aston University in Birmingham, England, used similar methods to investigate the issue. They both began by tossing food on three different floor surfaces - tile, laminate or wood, and carpet. However, while Clemson tested for just one bacteria - Salmonella typhimurium, and with just Bologna and bread, the Aston study involved a broader spectrum. The team not only tested for two kinds of bacteria - Escherichia coli and Staphylococcus aureus, but also, with foods ranging from dry toast to sticky candy. That's because they wanted to determine if food texture made a difference to the amount of bacteria picked up.
The results were similar in many ways. Both studies found that when food comes in contact with bacteria, the transfer is immediate. Also, the transfer is much larger when the food is dropped on tile, wood or laminate as opposed to carpet. Not surprisingly, moist foods like cooked pasta or candy are more efficient at picking up bacteria than foods like cookies or toast.
However, the conclusions the two researchers reached were drastically different. Professor Paul Dawson, the scientist heading the 2007 Clemson University study concluded that no matter what the surface or contact time, there is enough bacteria that was detected to make people sick. Not surprisingly, he recommends that anything that touches the floor should be immediately tossed.
Professor Johnson who led the Aston University study, the results of which were released on the school's website on March 10th, disagrees. He believes that the chances of picking up anything really nasty within five seconds, is very slim if you are in a place that you know is hygienically clean. Given that he has three young boys that are constantly dropping food, he can definitely attest to that. The professor does however recommend tossing food that falls in heavily trafficked places, like street sidewalks. That's because these areas have enough bacteria to make people sick, irrespective of how quickly the item is picked.
If you are one of those that diligently follows the five-second rule, don't fret. According to a survey done by the professor, a whopping 87% of people asked said they would or already had eaten food dropped on the floor. Of these 55% were women, 81% of which, had and will probably continue to follow the rule!
Resource: npr.org, news.nationalgeographic.com