Down for the count! The five-second rule isn’t true, a new study by Rutgers University reveals — but certain foods collect less bacteria than their counterparts.
According to a new study in the Applied and Environmental Microbiology journal, food acquires bacteria the instant it hits the ground, so the idea that morsels are germ-free if they’re snatched up within a certain time frame is false.
“We decided to look into this because the practice is so widespread,” study author Donald Schaffner said in a statement from Rutgers University. “The topic might appear ‘light’ but we wanted our results backed by solid science.”
The study examines four types of food: watermelon, bread, bread and butter, and gummy candy. Researchers dropped the food on four different types of floors — stainless steel, ceramic tile, wood and carpet — to see what combination of food and surface produced the most and least bacteria.
The foods were also dropped and left on the floor for varying amounts of time (less than one second, five seconds, 30 seconds and 300 seconds) in order to suss out whether the situation did indeed get worse the longer a piece of food sat on the floor.
Of the four kinds of food, watermelon proved to be the most attractive to bacteria because it had the highest concentration of liquid. Gummy candy took on the least amount of bacteria. Bread with butter attracted more bacteria than plain bread.
In terms of surfaces, carpet, perhaps surprisingly, transferred the lowest amount of bacteria, while stainless steel and ceramic tile transferred a lot. Wood depended upon quality of wood and other factors.
Long story short: Anything that falls to the floor will have some bacteria on it, though the amount is dependent upon what the food is, what the surface is, and how long the morsel stays on the ground.
