As a kid, I remember if I dropped a piece of food on the floor, I would quickly pick it up and deem it safe to eat because of the “five-second rule.” My friends and I always followed this so-called “rule,” and sometimes, even our parents would enforce it. But is it true that dirt and germs aren’t able to get onto the food item that quickly?
Jillian Clarke, a scientist in new product development who earned a Nobel Prize for her work, found that very little bacteria and very few microorganisms were able to attach onto the dropped food. Clarke conducted the study by placing gummy bears onto sterilized tile floors and floors ridden with bacteria such as E.coli. Although it wasn’t smothered in the bacteria, scientists warn us to be cautious nonetheless. “At least, wash it first,” says Ruth Frechman, MA, RD, the spokeswoman for the American Dietetic Association. “Bacteria are all over the place, and 10 types, including E. coli, cause foodborne illnesses, such as fever, diarrhea, and flu–like symptoms.” Washing food is important, whether or not it has touched the floor. Bacteria are everywhere, including our hands. Be careful to not cross-contaminate food while working with meats and other foods, and always wash utensils with soap and warm water. Food that is wet has more of a stickiness factor to it, which could attract more bacteria. Dry food won’t pick up the bacteria quite as easily. Meredith Agle, a doctoral candidate, claims that bacteria on the ground transfers onto food in less than five seconds, making this myth is an old wive’s tale that has no real truth behind it.
www.npr.org
Researchers at Aston University’s School of Life and Health Sciences found that, “Food retrieved just a few seconds after being dropped is less likely to contain bacteria than if it is left for longer periods of time. It also depends on what time of food was dropped and what time of floor it was dropped on. Bacteria are less likely to transfer from a carpeted flooring than a smooth wood or tile floor. Wet foods that were left for longer than 30 seconds on the floor had up to 10 times more bacteria than food picked up after only 3 seconds. So maybe the five-second rule should just change to the three-second rule and we will all be safe?
funny-pictures-quotes.com
Not quite. No matter the time the food was in contact of the floor, or the floors texture, some bacteria will still find its way onto that food item, but sometimes it might not be more than the bacteria that’s on your hand after touching things all day. “Even if something spends a mere millisecond on the floor, it attracts bacteria. How dirty it gets depends on the food’s moisture, surface geometry, and floor condition – not time.” These are only a few of the third-variable examples that are possibilities. The worst case scenario would be if you dropped your food onto a wet public bathroom floor or a dirty train station floor. This would obviously attract more germs and a variety of harmful bacteria as opposed to your private bedroom. The Mythbusters busted this myth for us. They say the transfer of bacteria is not based on time at all, but on other, more important factors. So the next time you drop your food, take the time to consider the floor and type of food you dropped- not how quick your reflexes are.
funny-pictures-quotes.com
There are many opinions from many different scientists on this matter, and until further studies are conducted, there is no way to tell if it will ever be 100% safe to eat food that has fallen on the floor just after a short five seconds, especially because each floor varies and people’s immune systems vary. More studies need to be conducted to determine when and where this rule could be safe. Of course, people with weak immune systems such as the elderly, young children, and people who are already sick should not live by the five-second rule. The way I see it is- the five-second rule is circumstantial, and depends on third variables, such as: If the food I dropped is dry pretzel on my own clean kitchen floor, I might quickly grab it and give it a little wipe-down, knowing I won’t come down with E.coli. If the food is wet, like a pineapple chunk, and it’s on a restaurant floor, I’ll toss it. If it’s a $20 steak, I’ll be more inclined to take the risk. Be careful, everyone. Don’t make yourself more susceptible to illnesses like Staph or salmonella, and always wash the food that has fallen!
That is a really interesting topic. In my home country China, really a great amount of people believe the 5 second rule. I always doubt it. I did learn from your post, because you not only provide scientist’s opinions and suggestions based on time, but also introduce other variables—floor conditions and food types to the topic. And I think it is not difficult to figure out whether the five-second rule works. Even though we cannot test all the floor conditions and food types, we could choose the most common one to look for some correlation. We can choose the campus dining hall as the constant variable. The X variable is the time a food dropped, and Y variable is the bacteria and dirt it attached. We could have a control group, which is normal food, and in the other group we intentionally drop the food on the floor for 5 seconds. And after that we use microscope to see what’s going on. We can have 5 to 7 tests with different food like beef, vegetable, bread, noodles, etc. I am sure there will be a strong correlation.
I thought that this was a really interesting post and I used to live by the 5 second rule! I never truly considered the differences in flooring, and in textures of food. It makes complete sense that bacteria would transfer quicker and more efficiently from harder floors as opposed to carpet. It also makes sense that foods that are more wet, such as fruits, would pick up more bacteria when dropped on the ground. I never pick up my food and eat it when I drop it in a public place, however, if I drop it on my own floor I am highly likely to eat it. After reading this I am not so sure it is worth the risk. Germs spread like rapid-fire especially in college, and everyone knows that you cannot afford to get sick. Great job!
I like that these studies dealt with a variety of foods and a variety of floors, in order to attempt to understand the results of the five second rule under various circumstances. In Clarke’s study, I think the use of a sterilized floor versus a floor with E-coli is effective in concluding which attracts more bacteria, but I don’t think it is as applicable to real life. Most floors aren’t completely sterilized and hopefully, others aren’t E-coli covered; most are probably in the middle. But you followed up that experiment with support telling people to continue to wash there food if it happens to fall. I think it is interesting that food on flat surfaces are more likely to attract bacteria than on carpet. I would have thought that carpet would contain higher amounts of bacteria and if food falls on it, the carpet would cover more surface area of the food, thus contaminating it. This article affirms my belief that people should be careful about eating food that they have dropped, but it also taught me to stop and consider the different variables involved because every situation is different. Of course I won’t think about it for too long though, that increases the risk of bacteria on my food!
I remember all the foods I ate off the ground when I was a kid and when someone gave me a weird look, I would just yell at them “5 second rule!” If you think about it, bacteria is literally everywhere. If you are eating a bag of chips, bacteria could be in the actual bag, on your hand as you pick up a chip, or in your mouth as you devour that chip. I agree that there are circumstances like what type of floor or how we he food is. It really depends on how strong our immune systems are, as each one is unique and reacts to germs in different ways. One could definitely expand on this and replicate more studies on this topic. One way you could further this topic of bacteria is to relate it to actual diseases like E.coli or even Ebola. What is the percentage of people who got sick from such diseases by just eating food off the ground. Of course, that would have to be an observational study where people who are sick are asked what they ate off the ground. You couldn’t have an experiment with this by making people eat food off dirty floors. The results would not be as strong from an observational study, but it is an interesting topic to expand on.
This blog post is very in depth and informative and considering I’m someone who abides by the 5 second rule I may possibly reconsider. I think it is commonsense to know that the texture/wetness of a food can affect how much bacteria is attracted, for example a slice of apple can visibly collect more “stuff’ from the ground whereas a chip may not. Using that knowledge, you can infer that bacteria would react the same. I think it would be interesting to find a study that tested specific foods in various areas. For example, a classroom floor that has a lot of foot traffic may possibly have more bacteria on the ground than the floor of someone’s living room. There are definitely more options to further this post, for example, suggesting other confounding variables that could impact bacteria, such as season, size of food dropped, and possibly time of day, just to name a few.
This article is very interesting because you not only looked at the five second rule but you also looked into the science and health behind it. I also liked how you went deeper into considering third variables like the type of floor or the type of food drooped. But some other ways to further the experiment could have been to look into the ways of making the five second rule safer. You ended your blog by saying how you should wash off the food that has been dropped, but which food, how effective is it, and how should we wash the food. The Food Safety and Inspection Service (FSIS) says that not all food should be washed. They say that washing items like raw meat could put yourself at risk for cross contamination. Also raw meats have some bacteria that is so tightly attached that it could not removed through washing (http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/safe-food-handling/washing-food-does-it-promote-food-safety/washing-food). A good way to further the blog would be to explain how to make the five second rule safer.