Are Birthday Parties Hazardous to Your Health?

Are birthday parties hazardous to your health?  Paul Dawson, et. al. published a study in the Journal of Food Research on 5/22/17 entitled “Bacterial Transfer Associated with Blowing Out Candles on a Birthday Cake”.   They compared the total number of number of bacteria and the number of different kinds of bacteria on a birthday cake, before and after blowing out the candles.  The test subjects ate pizza first, then blew out the candles.  The results showed that the bacterial transfer with blowing out candles caused a 1400% increase in bacteria on the cake after the candles were blown out.

They didn’t study the infection rate of people after attending parties, vs a control group.  They also didn’t measure the risk difference between eating birthday cake and any of a number of other activities in which people gathering together share germs via an endless list of opportunities.   I also wonder whether it may be a greater danger to be in the vicinity of the person while they are blowing out the candles, inhaling the aerosolized bacteria, compared with eating them mixed with the cake, and having the germs take a bath in the acid and enzymes of our digestive tracts.

You could consider everyone eating the cake having received a French kiss from or having shared the toothbrush of the one blowing out the candles.

So, what do you do with this information, other than say “pee-ew”?  Well, given the clear contamination documented, it would make sense not to have someone ill with a respiratory illness blow out the candles, especially if anyone in proximity has a weakened immune system.  One could ask, why they didn’t reschedule the party if they are sick?  You always have the option of not eating the cake.

Another consideration is many of us carry pathogens (organisms capable of causing disease) without being sick with them.  They can easily be transmitted the same way.  So, although the number of pathogens should be less, there are no guarantees.

These findings are not unexpected, but it sure is eye-opening when they are quantified.

Arnold Solof, MD