If you’ve always followed the so-called ‘five second rule’ for dropped food, you may want to rethink your dietary habits. According to newly published research from Rutgers University, it doesn’t really matter how fast you pick up food because it’ll already have germs on it by the time you retrieve it.
In fact, depending on the food items, germs may transfers in less than a single second… which is probably much less time than it takes you to notice the dropped food, bend over, pick it up, and uselessly brush it off.
The work was done by food science researcher Donald Schaffner and graduate student Robyn Miranda. While it may seem obvious to some, Schaffner points toward the pop-science belief that is still pervasive among some, saying, “We decided to look into this because the practice is so widespread.”
A total of four surface types were used in the testing: carpet, wood, stainless steel, and ceramic tiles. As well, the duo used four different types of food on these surfaces: watermelon, bread with butter, bread without butter, and “gummy candy.” Finally, they tested different durations each food item spent on the ground, including less than a single second, as well as five seconds, 30 seconds, and 300 seconds.
The various ground surfaces were contaminated with a non-pathogenic ‘bug’ similar to Salmonella. What the researchers found probably surprises no one: it’s not safe to eat any food you dropped, regardless of the ground surface, how clean it looks, or the food type.
The food drop tests were conducted a total of 2,560 times using various arrangements (time duration, ground type, food type, etc). Of these, bacteria transfer was fastest and more prevalent in cases where moisture was present, making the watermelon most contaminated. The gummy candy was the winner in terms of least amount of contamination.
Ground types, meanwhile, are a little different than anticipated, as carpet is the least likely to transfer bacteria compared to steel and tile.
Still, the researchers found that in some instances, and for all practical purposes, the transfer of bacteria to a food item can be instantaneous. Because the average person has no way of knowing whether it has taken place, it is best to throw dropped food away rather than risk eating it.
SOURCE Rutgers University