Does the Five-Second Rule Stand Up to Science? Apparently, it Does!

Is the five-second rule real? Germ scientists say it is.

On your mark.

Get set!

Go!!!

Your favorite candy falls out of your hand, makes a perfect drop shot onto the counter that would make even Serena Williams proud, and lands on the floor.

The race is on!

Germs begin racing to the morsel, ever on alert to spoil your fun.

But can you get there in time?!

5, 4, 3, 2, and SAVED!

Ha! Snacker 1, Germs 0.

And the crowd goes wild!!!

If this is how you imagine the microscopic race going down, you may be right. To a point.

Germ scientists tested the validity of the five-second rule, with surprising results. But where does the theory behind the five-second rule come from?

History of the Five-Second Rule

According to lore, the five-second rule is ancient. One historical reference suggests origins of the five-second rule can be traced back to Genghis Khan, of Mongol fame, and the “Khan Rule” he enacted at his banquets.

Five-second rule traced back to Genghis Kahn.

According to legend, the Khan Rule means that any food dropped on the floor can remain there as long as he [Genghis Kahn] permitted, saying that the food is good for five years.

In the 60’s Julia Child perpetuated this theory on an episode of The French Chef. Child flipped a pancake that landed on the stovetop instead of back in the pan. In only a way that Julia Child could, she took it in stride saying that you can always pick it up if you are alone in the kitchen.

We’ve ran with it ever since.

Why Do People Do This?

Why exactly do people decide to pick up a food off the floor and eat it? And how did we collectively decide that five seconds is the magic number? As for the reasons… There are several.

Quick Decisions

According to Williams K. Hallman, experimental psychologist and Rutgers University Professor, it comes down to quick decision shortcuts. He told The New York Times that not every decision receives a full risk-benefit evaluation. Instead, humans often rely on cognitive shortcuts to help with everyday decisions.

“It’s a way of making a very quick decision with whatever data is available,” said Hallman.

Unfortunately, these shortcuts can be a results of missing data or flawed assumptions. Sometimes that missing information could be a visual absence of harmful germs. These bugs are so small that we cannot see them without a microscope. It looks clean, it hasn’t been on the floor too long, it must still be good.

Personal Experience

If people have eaten food off of the floor in the past without consequence, they reduce the weight of the risk. The saying “I’ve always done it and never got sick,” or “I did this awhile back and nothing happened,” or “My grandad said it was ok,” are all likely excuses that have run through people’s minds at one point or another. This complacency builds habits.

Avoiding Food Waste

In some cases, we are so engrained not to waste food. Childhood lectures that “starving children would be grateful for those brussels sprouts, so eat them,” play on repeat in the back of my mind. Some people opt to eat the food that has fallen on the floor to avoid food waste.

Gender Differences

According to a few different polls, it seems that there is a gender difference when it comes to the likelihood of eating food that has fallen on the floor.

Men are more likely to engage in these types of behaviors, such as picking up a fork that has fallen to the floor or eat food that has hit the floor.

Men are more likely to engage in the five-second rule than women.

In another study, 81% of women asked if they would eat something that remained on the floor for more than 5 seconds said they would not eat it. This was the response for only 64% of men asked the same question.

Is There Truth to It?

So. Is there any truth to the five-second rule?

That depends on who you ask.

Germ scientist has mixed thoughts on the five-second rule, and even interpretations of the same study.

The Study

One study measured a few different food types, a few different surface types, and a several contact times to get a total of 2,560 measurements.

Foods included cut watermelon, bread, buttered bread, and strawberry gummy candy.

Surfaces included carpet, tile, stainless steel, and wood.

Contact times included less than one second, five seconds, 30 seconds, and 300 seconds.

The study found that carpet had the lowest rate of transmission of bacteria when compared to stainless steel and tile. Wood transfer rates varied, likely due to different porosities of the wood.

The study also determined that the composition of both the food and the surface matter more to germ transfer than the length of time it remains on the floor. For example, cut watermelon, with its moisture content, drew the highest rate of contamination. The gummy candy was the least contaminated.

Scientists Have Mixed Interpretations

The same data, interpreted by different germ scientists, can be interpreted in different ways.

For the most part, germ scientists stand behind the five-second rule, citing that depending on the surface, a minimal contact time provides less risk than longer contact periods.

Rejoice!

But wait…

Other germ scientists say it isn’t worth the risk.

According to the CDC, surface cross-contamination was the sixth most common contributing factor out of 32 outbreaks of food-borne illness. The floor is a surface, says the opposition.

According to the CDC, surface cross-contamination was the sixth most common contributing factor out of 32 outbreaks of food-borne illness.

According to these germ scientists, the statement that food dropped for a short period of time is “less likely to contain bacteria than if it is left for longer periods of time,” is incomplete. While there is a lower chance, that does not mean there is no chance or that the food is harmless.

Food dropped on the floor may still contain bacteria. Depending on your risk factors, this is a risk you may not want to take.

What Are Your Thoughts on the Five-Second Rule?

Are you pro- or anti-five-second rule? What are your thoughts?

Is food immediately destined for the bin if it drops to the floor? Or do you brush it off and pretend it never happened?

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If you’d like to know more about food safety topics in the news, like Does the Five-Second Rule Stand Up to Science?, check out the Make Food Safe Blog. We regularly update trending topics, foodborne infections in the news, recalls, and more! Stay tuned for quality information to help keep your family safe, while The Lange Law Firm, PLLC strives to Make Food Safe!

By: Heather Van Tassell (contributing writer, non-lawyer)