The ‘five second rule’ verified by science
by ofmiceandmolecules
Exam revision looms over your head, but the only way to motivate yourself is with M&Ms. A brightly coloured M&M is delicately balanced the top of each page of the textbook. Your tired, glazed eyes sweep over the text, trying to cram all the information in…a sentence left…and…done! You excitedly reach for the blue M&M, but you lose your grip. It flies in slow motion across the room and lands on the carpet.
What do you do? Leave it, or deal with it and have the next one once you finish the next page (no, taking another out of the pack is not an option)? Most people would leap across the room as fast as humanly possible to retrieve their prize.
The ‘five second rule’ states that any food that has been in contact with the floor for less than five seconds is still safe to eat. Well, it seems that science supports this excuse. Under certain circumstances, anyway. This is devastating news to a germaphobe like me.
The rationale behind the urban myth is that food that has been dropped for a shorter period of time has fewer germs. Research from Aston University provided the scientific basis for this urban myth, as they monitored the transfer of common bacteria from different flooring to dry, wet or sticky food.
They found that time, the underpinning factor of the ‘five second rule’, heavily influences the bacterial transfer. So the findings showed it is true that food dropped for a shorter time has less bacteria.
The type of flooring and food also seem to be important in your decision of whether to eat that piece of dropped food though. Carpeted surfaces were the least likely for bacteria transfer, whilst laminated or tiled surfaces were the most likely. The grace period is also longer with dry foods as opposed to sticky candy or wet foods like pasta.
That said, the data hasn’t been published yet or peer reviewed, so the preliminary findings have yet to be confirmed. The research should be taken with a grain of salt. Fecal bacteria hitching a ride on the soles of your shoes may end up on the floor of your dining room.
Anthony Hilton, the principle investigator of the study, warned “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; 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.”
Either way, I’m not playing Russian roulette with germs.
ofmiceandmolecules 
I’m not as much a germophobe as you are, and I really think this research is almost common sense: an M&M is delicious and hard and if it falls on the carpet I will eat it, but if the same were to happen to a gummy bear NO WAY would I eat it! Sticky=germs! (and admittedly if the M&M fell on my kitchen floor/the street it DEFINITELY would end up on the floor – my health is not worth an M&M.
But to answer your question I’d probably eat the next M&M on the list, and just move them all up a page… I’m not sure how I’d find the motivation to read that last page though, without an M&M reward! 🙂
Hi – thanks for commenting! I did think that it was common sense when I found the study, but also thought it was interesting (but also horrifying) enough to share with the world 🙂
Haha, I actually do this for revision, and I have a rule where I can’t move up the candy if anything happens to them (say, if someone nicked one, or if it fell on the floor), I just have to deal with it until I finish the next section and have the next one! It’s a bit of a daft rule, I do have to admit 😛
What kind of germs would we expect to find on the floor of, say, a normal house? Surely dropping your M & M in the house is less likely to be harmful than the pavement outside?
Hi Holly, thank you for commenting.
Common germs found at home include MRSA (a strain of S aureus), E coli, Novovirus and Clostridium difficile (that may cuse diarrhoea), according to NHS (http://www.nhs.uk/Livewell/homehygiene/Pages/common-household-germs.aspx)
I would assume that is correct, but you’d have to take into account of the environment of each household. Say, pets, or trailing germs in from outside when you walk into your home. Again, it also depends on the type of flooring – laminated tiles are much more ‘dangerous’ than carpeted floor.
So the longer you leave it on the floor, the more germs it will pick up. But what’s the limit before it just becomes absolutely rancid and it would be unwise to eat it? If I dropped my delicious sausage on the carpet 10 minutes ago could I still get away with eating it? Or will too much of that “fecal matter” have accumulated for it to be a good idea? This is what I wonder.
You can be my test subject at home if you want. I’ll leave a piece of food on our filthy kitchen floor for a different length of time, have you eat it and see if anything happens to you. good thing we live near a hospital, right?