Is It Really That Bad To Share Drinks? Here’s What Doctors Say.

Infectious disease doctors give the verdict on sharing backwash with your friends, kids or significant other.
You may want to think twice before sharing your water bottle with a friend.
skynesher via Getty Images
You may want to think twice before sharing your water bottle with a friend.

Three years ago, the idea of letting a friend take a swig from your water bottle would elicit panic and horror — the COVID of it all! But in this post-pandemic world (where COVID-19 still exists but we’re no longer panicking about it in the same way), we’ve collectively become less germaphobic.

Next time you meet a friend at happy hour, you may gladly hand over your cocktail for them to try. At colleges across the country, countless lips will make contact with the same red cup during drinking games. What are the risks really? Keep reading to find out when sharing is no big deal and when it’s better to keep your drink to yourself.

The Risk Of Sharing Drinks With Adult Friends

According to Dr. Bobbi Pritt, a pathologist and clinical microbiologist at Mayo Clinic, whenever you share a drink with a friend, there’s the potential of catching something. Some things aren’t too worrisome (like the common cold) and some are more threatening. “There’s a whole bunch of different types of microorganisms, bacteria, viruses, fungi and parasites. Some of them can survive in saliva,” Pritt said.

Some of these, she added, can survive on a dry surface (like the lip of a cup or opening of a straw) until they’re washed. That means it isn’t just the backwash that could potentially transmit something contagious.

Pritt explained that any situation that involves communal living (like college or military barracks) makes it easier to catch illnesses transmitted through air droplets from an infected person, such as meningitis. Living in close contact with other people combined with certain behaviours (like sharing foods and drinks) makes college students especially vulnerable to meningitis. “This is why teens are recommended to get the meningitis vaccine within five years of starting college,” explained Dr. Shivanjali Shankaran, an infectious disease specialist at Rush University System for Health.

Jennifer Dunphy, the chief population health officer at Regal Medical Group, shared that the more you swig, the greater your risk. The setting matters, too. “Crowded bars [are riskier], simply because there is less ventilation and a more likely chance of being closer to someone who is ill, but the type of drink generally will not influence the risk of contracting an illness,” added Dunphy, who has a doctorate degree in public health.

While we’re on the subject of bars, you should know that the alcohol you’re drinking won’t kill the germs. “Alcohol at a high level between 80% and 90% kills bacteria, fungi and viruses. But the most common form of alcohol we drink is ethanol and that concentration is about 12% in wine up to 40% in spirits,” Pritt explained.

Shankaran added to this, saying there isn’t much of a risk difference in sharing a drinking glass versus a water bottle. “The risk of acquiring an infection depends on the person who has the infection, such as how they are shedding the virus and bacteria and whether the inoculum, which is a part of the virus or bacteria that can start an infection, is sufficient to cause an infection,” she explained.

The Risk Of Kids Sharing Drinks With Each Other — And With You

Kids may not like to share their toys, but as every caregiver, day care worker and teacher knows, they have no problem sharing germs. If one kid leaves their juice box unattended, you can count on another kiddo picking it up and drinking out of it. Dunphy told HuffPost that kids sharing drinks is riskier than adults sharing drinks because kids tend to have more residual saliva than adults.

“If a child is sick, then more saliva will typically get into the beverage they are drinking, which means there is a higher chance of viral particles and mucus getting in the drink. This can lead to a higher chance of infection,” Dunphy said.

Kids often backwash more "residual saliva" and they're also more likely to have infections.
Frazao Studio Latino via Getty Images
Kids often backwash more "residual saliva" and they're also more likely to have infections.

Pritt said the types of risks for kids are the same as those for adults, but since kids get more infections, the likelihood of catching something is greater. “Kids get a lot of respiratory infections and those are transmitted through respiratory droplets of secretions, like saliva,” she said.

Seeing a kid drink out of another kiddo’s sippy cup may make you wince, but what about sharing drinks with your own child? Is sharing a glass of water, for example, a bad idea? In general, Pritt thinks sharing drinks with your child is fine — unless you’re super sick, because you don’t want to pass your illness to them.

“Preschool-age children tend to get sick more frequently because they do not have fully developed immune defences yet,” Dunphy said. “So by sharing a drink with a young child when you are ill, you have a higher chance of infecting the child and, if the child is sick and contagious, of becoming sick yourself.”

The Risk Of Sharing Drinks With Your Partner

The experts are in agreement that the least risky person to share a drink with is your significant other. After all, you’re swapping spit anyway when you make out. However, Dunphy emphasises that it isn’t totally risk-free.

“If you are regularly kissing someone who is sick, sharing a drink with that person only increases your risk of contracting the illness,” Dunphy said. “This is because there are certain times in a person’s infectious cycle that the viral load is highest and sharing a drink during that time would contribute to the overall viral burden. Although a healthy immune system is positioned to fight off viruses it comes into contact with, the more viral particles your body is exposed to — by kissing and sharing beverages — the larger the battle it is for your immune system to fight off,” she said. For that reason, she recommends not sharing drinks with your partner, at least when they’re sick, even if you do kiss them.

The bottom line is that any time you share a drink with someone, you’re at risk of catching something. But for airborne illnesses (like COVID and the common cold), Pritt points out that simply being around the infected person and breathing the same air is risky, too.

In general, Dunphy warns against sharing drinks — no matter who it’s with. “Sharing drinks is not harmless. It can lead to serious bacterial and viral infections that can have lifelong consequences. Any infection that can be spread through saliva can be spread through sharing beverages,” she said. “If you have to share a drink, the best way to do it is to pour it in a separate cup first or, as a last resort, to drink through a separate straw.”

It turns out that, sometimes, sharing isn’t caring. So if you can, keep your drink to yourself.

Close