Teresa Arnandis, biophysician: "Let's test whether the 3-second rule is a myth or has some basis in reality."

Can food that has touched the floor be eaten if it's picked up in less than three seconds? This is the question biophysician Teresa Arnandis poses at the beginning of a simple but revealing experiment. "We're going to test whether the 3-second rule is a myth or has some basis in reality," she states before putting this popular belief to the test. It's a widespread idea in homes and cafeterias, which maintains that food doesn't become contaminated if it's picked up quickly. But is this true from a microbiological perspective?

To analyze it, Arnandis performs a basic laboratory test . He drops a food item on the floor and, in less than three seconds, picks it up and places it on an agar plate . For comparison, he uses another identical piece that has not been in contact with the floor. Both samples are incubated at 37 degrees , the appropriate temperature for observing bacterial growth . The goal is to determine whether there is a noticeable difference in the presence of microbes .

After the incubation period, the results are clear : the food that touched the ground developed multiple bacterial colonies , while the food that didn't fall showed little contamination. The difference between the two samples confirms that contact with the ground, even brief, allows for the immediate transfer of bacteria . "Now you know that what falls on the ground isn't eaten," the expert concludes, thus dispelling a deeply held belief.

This simple experiment debunks the 3-second rule and warns of the real risks of eating dropped food . Even if picked up quickly, bacteria on the floor can instantly adhere . Therefore, it's prudent to discard any food that has touched the floor , regardless of how long it's been left. The scientific evidence is clear: there is no safe margin when it comes to food hygiene.