Those colorful candles burning brightly atop a birthday cake may look lovely, but apparently blowing them out has some pretty disgusting side effects, researchers say. A study in the Journal of ...

On average, blowing out the candles on a cake increased the amount of bacteria on the frosting by — wait for it — 1400 percent. Ick! But really, this isn’t a huge deal.

Despite that the Romans had dipped candles made from tallow going all the way back to around the 5th century BCE, it does not appear that they put candles on the birthday cakes, however.

His students stuck candles in, lit them, and blew. Oh actually, they did something before blowing out the candles: They ate pizza. “We also wanted to simulate a birthday party,” says Dawson.