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Is the five-second rule real?

Is the five-second rule real?

Do you follow the five second rule for dropped food? If so, this research, which uses a test bacteria with similar attachment characteristics to salmonella will be of interest :) . Longer Contact Times Increase Cross-Contamination of Enterobacter aerogenes from Surfaces to Food (Running title 'Is the five-second rule real?') :

The paper concludes 'Although this research shows that the 5-second rule is “real” in the sense that longer contact time result in more transfer, it also shows that other factors including the nature of the food and the surface are of equal or greater importance. The 5-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food.'

NewAtlas summarise the findings here:

So will this be a habit you'll now drop?


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I am writing this reply in Beijing, China, where hygiene standards are lower...and a "2-second rule" is a wiser choice. Sometimes friends rate restaurants along the lines of, "I love that place! I've eaten there a dozen times and never got food poisoned!"


My prior comment was flagged as "inappropriate," though I can assure you it's a fairly matter-of-fact statement, though intended to be humorous. When I first needed to receive FCR, I was advised by my US doctor to not go to China (where I perform much of my work) because it is too easy to get an infection or food poisoning when you are at your most vulnerable. I stayed out of China during that time period. But when I had to go through FCR a second time a couple of years later, I went to China anyway (despite my doctor's advice), for work, and flew to Tokyo for FCR treatments each month. Now I'm on Imbruvica, staring a bottle of it on my Beijing coffee table as I write this.

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What a fun article! I am going to use this in the microbiology class that I teach. Thanks for finding it.


Maybe the five second rule (for folks with normal immune systems, at least) work best if the rule has been in place since childhood. Children can be little petri dishes, but petri dishes never have a childhood (and the immunities developed there). I'm talking M&M's and Cheerios, though. The five second rule for pudding would be disgusting ;-) .


Hi. For me, personally, I would never follow this rule....pick something up that has landed where our shoes have walked, after they've been on pavements with all the dirt from others' shoes and dogs etc?! Regardless of any autoimmune problems, never! I don't understand when friends and family do!

Perhaps it's just me...? 😆xxx


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