You know, a cracker accidentally drops onto your kitchen floor and you promptly pick it up and pop it into your mouth. It seems that there is something to that old “5 second” rule after all. A professor and his students set out to test the theory and they made some interesting findings.
There is some risk to the “5 second” rule and it depends on the type and amount of bacteria on the floor, the type of floor, the type of food dropped, and the amount of time that the food stays on the floor.
- Food dropped onto a carpeted floor carries the least risk of bacterial transfer from the floor to the food.
- Laminated or tiled floors were most efficient at transferring bacteria.
- The longer the food stayed on the floor, the more likely it was to pick up bacteria.
- Moist food is more likely to pick up bacteria than dry food.
So it looks like you are pretty safe to continue (or feel free to start) the practice of eating food that’s been on the floor for 5 seconds.
Although the study didn’t go this far, it makes sense that even if the food picks up a little bacteria, the bacteria isn’t going to have a chance to reproduce once it hits the acid in your stomach. I think our germaphobe society prevents our immune systems from getting a good workout now and then to stay strong. Having said that, personally, I would only take the “5 second” rule so far—if the food falls on the food court floor, into the trash it goes.
The study also didn’t look at food dropped on the floor and put back into storage. In that situation, the bacteria would have a chance to grow, even in the refrigerator or freezer–not a very appetizing thought.