Is there any truth to the "Five-Second Rule?" Researchers actually decided to find out.
Many of us are well-aware of the urban myth in which food that has been dropped on the floor can be eaten if picked up quickly. Although this rule appears to be more widely utilized for things such as chocolate instead of broccoli, should it utilized at all?
Researchers at Clemson University published the first and only peer-reviewed journal article about the "Five-Second Rule" in the Journal of Applied Microbiology.
"We wanted to know if the length of time food is in contact with a contaminated surface affected the rate of transfer of bacteria to the food," said Dr. Paul Dawson, professor of Food Science at Clemson University.
Dawson’s team contaminated pieces of carpet, tile, or wood with Salmonella bacteria. Five minutes later, researchers placed bread or bologna on top for five, 30, or 60 seconds. The procedure was also replicated after the surface had been contaminated for two, four, eight, and 24 hours.
In the end, the amount of bacteria was not dependent on how long the food was placed on the surface. However, the degree of contamination did play a role, and certain surfaces absorbed more bacteria than others.
"Carpets, for instance, seem to be slightly better places to drop your food than wood or tile," Dawson explained. "When carpet was inoculated with Salmonella, less than 1% of the bacteria were transferred. But when the food was in contact with tile or wood, 48%-70% of bacteria transferred."
Although the chances of "extremely virulent" bacteria being on most surfaces is quite low, we might want to reconsider using the "Five-Second Rule."
"So the next time you consider eating dropped food, the odds are in your favor that you can eat that morsel and not get sick," Dawson said. "But in the rare chance that there is a microorganism that can make you sick on the exact spot where the food dropped, you can be fairly sure the bug is on the food you are about to put in your mouth."