Everybody does it. Well, at least 87 percent of people admit to
doing it: eating food that has been dropped onto the floor. That is
one of the findings in a new study on the transmission of bacteria to
food conducted by students at Aston University in Birmingham,
U.K. The study offers a bit of support to the longstanding "five
second rule" that many people invoke when it comes to dropped food.
The study found that the longer food rests on the floor, the more
bacteria will hop on to it. This contradicts a finding by the hosts of the television show
However, both this study and the Mythbusters agree that
the type of food and floor surface play significant roles in
determining how much bacteria is transmitted. Wet or sticky foods
(the students tested toast, pasta, biscuit, and a sticky sweet)
picked up more bacteria, but surprisingly, carpet transferred far
fewer bacteria to food than hard surfaces like tile or linoleum.
Professor Anthony Hilton, who oversaw the study, noted that "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."
While eating food off the floor still carries a risk that you
will pick up infectious bacteria, people can take some solace that
following the five second rule enjoys a bit of supporting science.
Will these findings change your mind about eating dropped food?