Don't Trust the 5-Second Rule!
What is with the five-second rule about food that falls on the floor?By Linda BrowneHave you ever found yourself in this predicament? You get ready to take a big, satisfying bite out of that long-awaited treat when suddenly a chunk of it cracks off and falls to the floor. In a moment of quick thinking (or rather, a lack thereof), you scoop it up and shove it into your mouth, hopefully before anybody notices. Donât judge; weâve (likely) all been there! But you managed to pick it up within five seconds, so itâs all good, right? The âfive-second ruleâ is one that many of us have invoked time and time again to minimize food waste (or just because we really, really wanted that gummy bear). But you may want to second-guess that âruleâ before you put another bit of floor food into your mouth. In their book Donât Swallow Your Gum!: Myths, Half-Truths, and Outright Lies About Your Body and Health, Drs. Aaron Carroll and Rachel Vreeman (both professors of pediatrics at the Indiana University School of Medicine) examined a study that put the five-second rule to the test. The study, published in the Journal of Applied Microbiology, looked at the survival and transfer of Salmonella typhimurium from wood, tile or carpet to bologna and bread. It concluded that Salmonella âcan survive for up to four weeks on dry surfaces in high-enough populations to be transferred to foods andâ¦ can be transferred to the foods tested almost immediately on contact.âIn this study, the âworst offenderâ of the five-second rule, explain Carroll and Vreeman, was bologna on tile. âOver 99 per cent of the bacterial cells transferred from the tile to the bologna after just five seconds of the bologna hitting the floor!â they write.âTransfer from wood was a bit slower (five to 68 per cent of the bacteria was transferred) and transfer from carpet was actually not very successful. After hitting the carpet, less than 0.5 per cent of the bacteria transferred to the bologna. When they did transfer, bacteria moved to the food almost immediately upon contact. By five seconds, it was too late.âCarroll and Vreeman note that itâs not just bacteria that people should be concerned about when their food hits the floor. âA study of pesticides on household surfaces shows that these toxic chemicals can also transfer to foods like apples, bologna and cheese. The pesticides seem to take a little longer than bacteria, though.âSo the next time you drop that piece of chocolate on the floor, forget about the five-second rule and send it straight to the trash.