Blowing Out Birthday Candles? Suprising Hygiene Concerns You Didn't Know About

Blowing out candles on a birthday cake is a cherished tradition worldwide, but have you ever stopped to think about what really happens when you do it? It may seem harmless, but research suggests otherwise. With every breath used to extinguish the flames, countless saliva droplets, and the bacteria they carry, land directly onto the cake’s surface.

Blowing Out Birthday Candles: How Hygienic Is This Tradition? What the Study Reveals

A study published in the Journal of Food Research in 2017 found that this simple act increases bacteria on the cake’s frosting by a staggering 1,400%. The study, conducted by six researchers (Paul Dawson, Inyee Han, Danielle Lynn, Jenevieve Lackey, Johnson Baker, and Rose Martinez-Dawson), aimed to measure the bacterial transfer from blowing out candles. 

Instead of real cakes, they used frosting spread on foil to mimic a cake. Participants were first asked to eat pizza to stimulate saliva production and then blow out the candles. When the frosting samples were analysed, researchers found a significant increase in bacteria compared to untouched frosting.

While the average increase was 1,400%, the amount varied among individuals. Some blowers transferred only a small amount, while in one case, bacteria levels spiked by 120 times. The findings suggest that the risk depends largely on the person blowing the candles.

Should You Worry?

Despite the increase in bacteria, experts suggest that it may not necessarily lead to illness. The human mouth naturally contains bacteria, and not all are harmful. However, the study does highlight a potential hygiene issue, especially in situations where multiple people share the cake.

Some may dismiss these findings as insignificant and continue the tradition without concern, while others might rethink their approach, especially for young children, the elderly, or those with weak immune systems.

Alternatives to the Tradition

For those worried about hygiene, here are three simple alternatives to keep the celebration germ-free:

Wave the Candles Out: Instead of blowing, gently wave your hand to extinguish the flames. This keeps the tradition alive while minimizing the spread of bacteria.

Use Sparkler Candles: These special candles burn out on their own, removing the need to blow while adding an extra spark to the celebration.

Opt for Cupcakes: Instead of a big cake, serve individual cupcakes. This way, each person gets their own, reducing the risk of sharing germs.