We're talking about whether or not you should eat your last truffle, which has just fallen on the floor. We understand if your reflexes are slow; you've just dropped that luscious piece of chocolate, and most people's immediate reaction is to scream "Noooo!" or mutter some choice expletive rather than diving for the fallen piece of chocolate.
But then it occurs to you: the Five-Second Rule. If you dive for it, that chocolate is still legit. But how much time has passed since the travesty occurred? And how fast can you dive to the floor to get your truffle back? All this runs through your mind like an Olympic sprinter; it's do or die.
But will it be do and die? Is the Five Second Rule even valid?
To find out, the enterprising investigators at the Mess have conducted a study. A very serious, very scientific study. We put on our lab coats, busted out our rubber gloves and wandered into the Cage. Then we started droppin' food like it was hot. Specifically, we dropped it like it was hot for five seconds, 10 seconds and two minutes. Like good little scientists, we included two control samples, which were not casually thrown on the floor. Also, figuring that a sticky piece of food might pick up more bacteria than something dry, we decided to include cucumber slices and chunks of bread in the test.
After we exposed our food to the Cage floor, we used sterile swabs to transfer bacteria from the exposed surface of the food to plates of bacterial growth medium. Then, we let the dishes sit for about four days. (Escherichia coli forms visible colonies within a couple days.)
While we waited, we dove headfirst into Five-Second Rule research and literature. Believe it or not, scientists wonder about the same things as the rest of us, and they most definitely want to know how long it takes for food to become contaminated.
Clemson University researchers, in a study conducted in 2006, found that the type of floor surface upon which the food was dropped was very important in how much bacteria collects on the sample. They discovered that food exposed to carpet surfaces picked up less bacteria than food left on hardwood or tile floors. Since the floor of the Cage is tile, we were prepared for the worst.
Clemson's experiment was only one of several studies conducted on this subject. According to a study conducted in May 2007 on the popular television show "Mythbusters," food could become contaminated with disease-causing bacteria in as little as two seconds. Adam Savage and Jamie Hyneman, our counterparts on "Mythbusters," concluded that how long a piece of food remains on the floor is not as important as how dirty the floor surface is and how much surface contact occurs between the floor and the piece of food. Also, they found that moisture content of the food makes a drastic difference in bacterial uptake.
Having done our homework, we came back to check our bacterial growth plates. We were mildly perturbed to see that a number of colorful fungi, molds and bacteria had grown on the surfaces of our plates.
We determined that there were at least three types of bacteria on the plates, one of which was the bacterium E. coli. Rhizopus, a black bread mold, was also present on two of the bread samples.
Our bread results were inconclusive. There was not a strong correlation between the amount of bacteria present on our plates and the duration of the exposure. Our bread control sample grew more bacteria than our 10-second and two-minute exposures, as did our five-second exposure.
However, our cucumber results were extremely conclusive. Due to their moisture content, our cucumber plates showed a larger amount of bacterial growth than the bread did, consistent with the "Mythbusters'" findings. The plates all grew a roughly even amount of bacteria. Our five-second plate had the same amount of bacteria as our 10-second and two-minute samples, though all three grew more bacteria than the control.
So, is the Five-Second Rule still valid? Probably not. From our study, we learned that the moisture content of the dropped article of food has a lot more to do with the amount of bacteria uptake than the duration of the dropping. So, think twice before you pick up that apple slice or grape that you so gracelessly dropped to the floor. Depending on the bacteria, it can take as few 10 cells to make you sick. And our cucumber plates were sporting far more than 10 cells of bacteria.
Plus, the Five-Second Rule says nothing of the various chemicals and cleaning solutions that might be on the floor, which makes it even less safe to chow down on floor-food, as tempting as that solitary french fry may be.