Don’t Double-dip That Chip!

SPRINGFIELD — OK, admit it. You’ve bitten into a potato chip or cracker covered in onion dip, then dipped it again.

“Not a good idea,” said Mary Ellen Scales, chief Infection Control officer at Baystate Medical Center, even if you’re the only one using it at home, and then putting it away in the refrigerator for your next snack.

“It is a well-known fact that mothers who serve babies from a jar of baby food and then place it in the refrigerator risk their baby getting sick when he or she is fed the remainder later on,” said Scales.

The Urban Dictionary describes double-dipping as a “generally frowned-upon act where a person at a party with snacks dips a chip he/she has already taken a bite out of into the dip a second time.”

A popular Seinfeld episode, in which character George Costanza is caught in the act of double-dipping, added fuel to the fire that the practice spreads germs.

“Double-dipping is socially unacceptable and runs the risk of passing things like cold sores and influenza to others. Be aware of those who also like to lick the serving spoon, taste the sauce or soup-stirring spoon, or lick their fingers in the buffet line,” said Scales.

MythBusters hosts Adam Savage and Jamie Hyneman from the Discovery Channel put the belief to the test. Their website reports that, by testing bacteria grown in petri dishes using sterilized chips and a salsa-like substance, they found that double-dipping adds just a small amount of bacteria to the salsa, and definitely not as much as sticking your mouth in the bowl.

“The truth is that most dips — store-bought or homemade — already contain bacteria, and double-dipping adds only a few more microbes than the multitude swimming in your salsa to begin with,” reports the website.

On the other hand, the Scientific American website suggests that, “if you detect double-dippers in the midst of a festive gathering, you might want to steer clear of their favored snack.”

The website reported on an undergraduate research team at Clemson University that created various experiments to learn what happens when someone double dips. The researchers found about 1,000 more bacteria per milliliter of water when crackers were bitten before dipping, than in solutions where unbitten crackers were dipped.

They also found that, “in the absence of double-dipping, our foods had no detectable bacteria present. Once subjected to double-dipping, the salsa took on about five times more bacteria (1,000 bacteria/ml of dip) from the bitten chip when compared to chocolate and cheese dips (150-200 bacteria/ml of dip).”

It is well-known that many different bacteria and viruses live in the human oral cavity. Many are harmless, others not, such as pneumonic plague, tuberculosis, influenza virus, Legionnaires’ disease, and severe acute respiratory syndrome (SARS) — all of which spread through saliva.

So, what to believe?

“Once again, remember that food can be contaminated with saliva,” said Scales, who suggests the use of single dip/chip serving pieces for party goers. “Keep healthy, and protect others if you are sick, by not double-dipping at parties or other occasions.”