“You’re not going to eat, are you?” your friend wonders as you reach down to grab the cookie you just dropped on the floor. “Five-second rule!” you say, before popping the cookie into your mouth.
According to this popular belief, if you drop a piece of food on the floor and pick it up within five seconds, it is safe to eat. The suspicion is that bacteria on the floor do not have enough time to hitch a ride on the food. But is it true?
In 2003, Jillian Clarke, a senior at Chicago High School for Agricultural Sciences in Illinois, said: Put the five-second rule to the test. She inoculated two types of tiles – smooth and rough – with Escherichia coli and dropped gummy bears and cookies onto the tiles for five seconds. Clarke and her colleagues saw that bacteria entered food very quickly, in just five seconds, challenging the popular belief.
A few years later, nutrition scientist Paul Dawson and his students at Clemson University in South Carolina also tested the five-second rule and published their results in the Journal of Applied Microbiology. When they dropped bologna sausage on a piece of tile that was contaminated with Salmonella typhimuriumMore than 99% of the bacteria were transferred from the tile to the bologna after just five seconds. The five-second rule was fair nonsenseDawson concluded.
But in 2014, microbiology professor Anthony Hilton and his students at Aston University in the United Kingdom reignited the debate. They studied the transmission of E.coli And Staphylococcus aureus from a variety of indoor floor types (carpet, laminate and tiles) to toast, pasta, biscuits and a sticky sweet, with contact times ranging from three to 30 seconds. According to their results (which were shared in a press release but not published in a peer-reviewed journal), the longer a piece of food was in contact with the floor, the more likely it was to contain bacteria. This could be interpreted as evidence in favor of the five-second rule, Hilton noted, but was inconclusive.
This prompted food scientist Donald Schaffner and his master’s thesis student Robyn C. Miranda at Rutgers University in New Jersey to conduct a study rigorous study about the validity of the five-second rule, which they published in the magazine Applied and environmental microbiology. They looked at the transfer of bacteria to four different foods (watermelon, bread, bread and butter, and gummies) when they fell on four different surfaces (stainless steel, ceramic tile, wood, and carpet) that were contaminated with Enterobacter aerogenes. Analyzing bacterial transfer at <1, 5, 30 and 300 seconds, they found that longer contact times resulted in more transmission, but some transfers occurred 'instantly', after less than 1 second, breaking the five-second rule for once debunked. for everyone.
Your chance of getting sick after eating food that has touched the floor depends on factors such as how contaminated the floor is and the type of bacteria present. “Our research shows that the kitchen floor is one of the most contaminated places in the home,” Charles P. Gerbasays a microbiologist and professor of virology at the University of Arizona Popular science. Believe it or not, “the kitchen is actually germier than the toilet in the house,” he added. This is because, compared to other rooms in a house, the kitchen receives a lot of foot traffic and food scraps often fall to the floor, creating an ideal breeding ground for bacteria. While most bacteria lurking on the kitchen floor are harmlesssome – like Clostridium, Campylobacter, SalmonellaAnd Escherichia– can cause food poisoning.
If you simply hate throwing away food, there are safer options than relying on the five-second rule. Rinsing dropped food can reduce contamination, although this method is not foolproof. “Rinsing is a good idea when it comes to fruits or vegetables, but it is more difficult to rinse microbes from meat because of their rougher surface,” says Gerba. “You should also rinse food if it falls into the sink because it is also very germy due to the moisture in the sink,” he suggested.
The next time you’re tempted to eat that cookie you just dropped, remember: bacteria move fast. No matter how hungry you are, do you really want to eat a Salmonella-laced cookie?
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