You may want to reconsider this birthday tradition for the sake of the cake.
Blowing out the candles on your birthday cake: Most people have been doing it since childhood. They don’t question the tradition. It happens at every birthday party, especially celebrations for kids—runny-nosed, sneezing, hands-covered-in-dirt kids. Given that information, perhaps it shouldn’t be surprising that scientists recently discovered that this hallmark of birthday parties might be ruining the cake. We guess we should have seen this coming.
In the newly released issue of the Journal of Food Research, a study called “Bacterial Transfer Associated with Blowing Out Candles on a Birthday Cake.” Scientists suspected that blowing on your cake might actually spread germs from your mouth out onto the cake’s icing, which sounds obvious when you take a second to think about it. To prove their claims, they spread a layer of icing onto foil and placed birthday candles on top. They asked participants to eat a slice of pizza, and then “extinguish the candles by blowing.”
Here’s where things get a little gross: Once the researchers tested samples, they found that the number of bacteria on the icing had increased by 1,400 percent after it was blown on.
Yes, that is a disturbing factoid. But if you are reading this in the middle of your child’s birthday, there’s no need to cruelly cancel the festivities mid-party or throw the cake in the trash.
The Atlantic happened to call up Paul Dawson, a professor of food safety and one of the study’s authors, to figure out whether or not we need to be worried about that germ infested birthday cake we’ve been eating over the years.
“It’s not a big health concern in my perspective,” he says. “In reality if you did this 100,000 times, then the chance of getting sick would probably be very minimal,” he told the magazine.
Your germ-coated cake is still totally edible. Just try to forget all about this study next time you’re singing "Happy Birthday."