Why You Should Stop Blowing Out The Candles On Your Birthday Cake

"Happy birthday to you, happy birthday to you, happy birthday to yooou, happy birthday to you." We all know what comes in the following moments of excitement and joy — the blowing out of the ceremonial candles on the cake. This innocent and seemingly age-old gesture has good intentions but can be more harmful than you'd think.

Whether we are simply talking, singing, yelling, coughing, or sneezing, our mouths and noses produce aerosols and droplets. These aerosols and droplets come out naturally and unknowingly, and usually go unseen, but they are not harmless. Respiratory illnesses like SARS and H1N1 influenza are known to spread through oral airborne transmission. Once the droplets are expelled through the mouth or nose, bacteria and viruses can spread either directly, person-to-person, or indirectly, through contaminated surfaces.

A 2017 study looked at the spread of bacteria on a birthday cake with blown-out candles. What they found was alarming — the icing on a cake in which candles were blown out showed approximately 1400% more bacteria than the icing on a cake without candles. Now that cake isn't looking so appealing, huh?

Dr. David M. Aronoff, director of Vanderbilt University Medical Center's Division of Infectious Diseases, tells Today that blowing out candles actually sends out droplets a longer distance than simply breathing or speaking. We now know that a significant portion of people infected with SARS-CoV-2, the virus responsible for the COVID-19 infection, never develop symptoms. Dr. Aronoff goes on to say, "This is problematic because it could be the case that the person blowing out the candles is infected with SARS-CoV-2 and does not know it. Blowing their breath out with force could project virus particles a greater distance," and infect others in the surrounding vicinity.

So how can you safely still honor the tradition of having birthday candles without spreading germs? Thankfully, humans have always had the ability to adapt to the ever-changing world. A few alternatives to the conventional method include using a paper or handheld fan to extinguish candles, or even to give the birthday girl or boy their own individual cupcake with a candle they can safely blow out without contaminating everyone's slice.

There are also a few patents for a cake shield. You heard that right, earlier this year, dentist Billy Kay developed a cake shield to protect the coveted birthday cake. The shield covers the entire cake and you can place candles over the cover to safely blow out.

So the next time you're celebrating a special occasion, consider the risks of birthday candles, and help keep those around you safe and healthy!