10 March 2014
The findings suggest there may be some scientific basis to the ‘5 second rule’ - the urban myth about it being fine to eat food that has only had contact with the floor for five seconds or less. Although people have long followed the 5 second rule, until now it was unclear whether it actually helped.
The study, undertaken by final year Biology students and led by Anthony Hilton, Professor of Microbiology at Aston University, monitored the transfer of the common bacteria Escherichia coli (E. coli) and Staphylococcus aureus from a variety of indoor floor types (carpet, laminate and tiled surfaces) to toast, pasta, biscuit and a sticky sweet when contact was made from 3 to 30 seconds.
The results showed that:
Professor Hilton said: “Consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at the time; however the findings of this study will bring some light relief to those who have been employing the five-second rule for years, despite a general consensus that it is purely a myth.
"We have found evidence that transfer from indoor flooring surfaces is incredibly poor with carpet actually posing the lowest risk of bacterial transfer onto dropped food."
The Aston team also carried out a survey of the number of people who employ the five-second rule. The survey showed that:
Our study showed that a surprisingly large majority of people are happy to consume dropped food
Professor Hilton added:“Our study showed that a surprisingly large majority of people are happy to consume dropped food, with women the most likely to do so. But they are also more likely to follow the 5 second rule, which our research has shown to be much more than an old wives' tale.”
Note: This research has not yet been peer-reviewed. If you would like a copy of the report or require further media information, please contact Jonathan Garbett, Aston University Communications on 0121 204 4552 or firstname.lastname@example.org