Confessions of a '5 second rule' breaker
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I am a board-certified infectious disease physician and an unashamed and unrepentant “5 Second Rule” breaker.

The infamous “5 Second Rule” was never really an actual rule based on science and that is why I never adhered to it. Its most recent debunking provides an opportunity, however, to explore the notions of sterility and bacterial contamination that it was meant to address.

The idea behind the “rule” was that a certain amount of time must elapse before a piece of food could be contaminated by bacteria residing on the floor, ground, or surface to which a previously perfectly edible piece of food had perilously fallen. In this race against time, the swiftest picker-uppers were, purportedly, spared the experience of eating bacteria-laden food. The newest bit of research has shown that it takes just one half second for bacteria to transfer from surfaces to food.

To anyone who understands the rudiments of microbiology the “5 Second Rule” was never something that even merited extensive study for it was clearly arbitrary and not supported by well-established scientific facts. What the “5 Second Rule” and all the idyllic aspirations of a sterile world neglect to consider is that our planet is one that is utterly dominated in almost every biological aspect by bacteria. The Earth literally teems with bacteria that thrive everywhere. The air, the stratosphere, the thermal vents on the ocean floor, and our bodies are all home to countless bacteria. In fact, we would literally not be able to perform vital bodily functions such as digestion and efficient blood clotting without the bacteria that inhabit our bodies.

Food, the plates that it is served upon, the utensils employed to eat it, the air that surrounds it, and the fingers that touch it are not even close to sterile. It really is silly to think that food somehow is miraculously spared from the hordes of bacteria that have been almost the exclusive inhabitants of this planet for most of the approximately 4 billion years that have passed since life first appeared. Thankfully our cave-dwelling ancestors, who obtained sufficient nutrition to flourish to such a degree that we are here today, probably did little more than brush the visible dirt from their food before consuming it.

However the fact that we ingest bacteria with every bite of every meal does not mean that all bacteria are benign. Anyone who peruses the headlines is familiar with reports of outbreaks of various bacterial foodborne illnesses, some of which are deadly. Improperly cooked food, poor hygiene in food preparation, lack of pasteurization, and contamination with fecal matter are all very dangerous and serious problems that take a major toll on our species.

But the very real problem of foodborne infections is not what the “5 Second Rule” was ever about. This misguided “rule”, in my estimation, shares its origin with such phenomena as the demand for antibacterial soaps for ordinary household use.

Following basic hygienic principles, such as refraining from eating food dropped in a field strewn, for example, with cow dung is unequivocally important to maintain but an over concern for the unachievable and ill-advised ideal of sterility is another thing altogether.

Dr. Adalja is a board-certified infectious disease physician. Read his blog at and follow him on Twitter (@AmeshAA).

The views expressed by contributors are their own and not the views of The Hill.