You’re about to eat the most mouthwatering, amazing, and best food in the whole world. Suddenly, it slips from your grasp (halfway towards your mouth, I might add) and tragically plummets to the ground. In this situation, I’m sure many people would adhere to the ‘five-second [or three-second] rule’. They’d hastily pick the food up, brush it off a bit, and be on their merry way as if nothing happened. But can we really assume that retrieving food within five seconds of it being dropped is safe? Hmm…
It’s weird because the five-second rule is a bit subjective. You wouldn’t apply it to dropped ice cream would you?
The five-second rule seems to apply itself on a case-by-case basis, depending on things like the type of food you’ve dropped, the type of surface you’ve dropped it on and how hungry you are. I’m sure the hungriest person in the world wouldn’t have any problem eating icecream off the mud it’s been dropped in. I guess the question of whether or not you choose to eat the food depends on the level of risk you perceive the food in having gained, during those few short moments on the ground.
Although the five-second rule doesn’t sound at all scientific, it is logical to assume that food that is retrieved after just a few seconds on the ground would have attracted less bacteria than food that has been left to linger on the ground longer. And researchers have actually found that although initial impact with the ground transfers a small amount of bacteria to food almost immediately (i.e. in under five seconds), it can attract up to ten times more bacteria after being there for 30 seconds.
One determinate of the speed and amount of bacterial transfer is the type of food dropped. Moist foods pick up more bacteria faster than dry foods do. Another determinate is the type of surface the food has been dropped on. Dropping food on carpet, for instance, would give the slowest rate of bacterial migration when compared to all other surfaces. This is due to the amount of contact the food makes with the floor – smooth surfaces have a larger area of contact compared to fibre tips on carpet.
So the moral of the story is that if you’re counting on having no bacteria get onto your food after dropping it, you’re out of luck. However if you’re really, really hungry and still want to eat it, pick up the food as quickly as possible. But only if it’s dry. Otherwise gross.
Featured image is sourced from http://media.npr.org/assets/img/2014/03/14/five_second_wide-7e64de8e593b2349a9b8fe5ea5bad711f71e1f55-s40-c85.png.