This Is Why Blowing Out Candles On A Birthday Cake Is Bad For Your Body

Making a wish and blowing out the candles on a birthday cake is something we all look forward to (even if maybe the thought of celebrating another birthday makes us cringe). And although the act is nostalgic and fun, the truth is: blowing out birthday candles is kind of gross.

In his new co-authored book with Brian Sheldon, Did You Just Eat That? Two Scientists Explore Double-Dipping, the Five-Second Rule, and other Food Myths in the Lab, food scientist Paul Dawson explores the old food myths that make us believe eating tainted food is okay. In an interview with MUNCHIES, Dawson revealed that our food can become riddled with germs and bacteria faster than we can say “happy birthday.”

“One [instantaneous transfer of germs] was blowing birthday candles out,” Dawson said of his scientific research. “We found pretty high levels of bacteria in some cases.”

Yup. Anytime a birthday boy or girl blows out those candles, they’re projecting mouth germs and bacteria onto the cake, which is then consumed by unsuspecting friends and family. Gross.

“Actually,” Dawson continued, “I found while researching other studies that these bacteria are flying out of people’s mouths even just in conversation.” Literally no one is safe from germ transfer, unless you live in a plastic bubble.

Dawson and Sheldon’s findings also completely debunk the classic “five-second rule.”

You know the one: if a piece of food is on the floor for less than five seconds, it’s safe to eat because potential bacteria has yet to transfer.

“Bacteria don’t have to jump; they make contact on the surface,” Dawson told MUNCHIES. “We found that there’s significant differences in bacteria accumulation over time, but even though there’s differences between five seconds and 60 seconds, there’s still immediate transfer.”

But, as revolting as all this germy food talk is, there’s good news. Even if you ingest a piece of cake with your pal’s germs on it, or eat something off the floor, chances are you’ll be fine. Dawson noted that most surfaces don’t have harmful pathogenic bacteria on them.

In reality, we’re all constantly playing a game of food Russian Roulette. How many times can we eat a piece of bacteria-laden birthday cake before biting into the slice that will make us sick?