There’s no reason to cut out your favorite birthday tradition.
This month, Clemson University released a study that might have put germophobes and cautious parents on edge. In the study, researchers found that blowing out candles on a birthday cake resulted in 1,400 percent more bacteria spread over the surface of the cake.
Of course, blowing out candles—especially for little ones—is a birthday tradition many would prefer to hold onto. The good news: you can, according to Philip M. Tierno, Jr., PhD, professor of microbiology and pathology at NYU.
Blowing out candles does transmit some germs—and when those germs settle on the surface of the cake, anyone who eats the sweet treat could technically get sick. This is called indirect contact, meaning there is no actually contact physical between you and the sick person, but instead first from the sick person to the cake and then the cake to you. When taken out of context, the increase in germs cited in the study sounds alarming. But the truth is most people have immune systems capable of fighting off any extra germs that make their way onto the cake. In an abundance of caution, kids, the elderly, and anyone else with weakened immune systems who may not be able to fend off germs as easily might consider skipping.
In general, though, we interact with far germier things on a daily basis. “Activities that involve multiple people, like [interacting with an] ATM machine, increases risk of infection far more than one person blowing out candles,” Tierno says.
Since there is no way to avoid bacteria entirely, there's no reason to cut your favorite birthday tradition out completely—you may as well go ahead and let the birthday boy blow out those candles... and then eat the slice that's passed your way. One caveat: If the guest of honor has been sneezing or coughing all day, Tierno says, consider giving them an individual cupcake to blow out or sing, smile, and save your appetite for later.