Health Experts Warn Against This Common Parenting Habit

Some parenting habits are so routine, you probably don’t give them a second thought. Maybe you taste your child’s food with a spoon before handing that same spoon to them, blow on a too-hot bite before giving it to them or take a sip from the same cup before handing it over.

While these moments may seem completely harmless, sharing food in this way involves something you might not have considered: saliva transfer.

There’s no need to panic over every shared bite or sip, but paediatric health experts say it’s worth understanding how saliva-sharing can affect your family’s health, and how simple changes can help reduce unnecessary exposure.

One concern health experts have about saliva transfer is that it can introduce Streptococcus mutans, the primary bacteria responsible for tooth decay, into a child’s mouth.

These bacteria feed on sugars and produce acids that can wear away tooth enamel. “Babies are not born with the main cavity-causing bacteria, so these germs are usually passed to children from a parent or carer through saliva,” said Dr. Soha Sharif, children’s dentist at Pure Dentistry.

“If a child’s mouth is colonised by these microbes early on, there’s a greater risk of them developing early childhood tooth decay.”

The caregiver’s oral health can make a difference, too. If they don’t have untreated decay, active gum disease or a mouth infection, any saliva that reaches the child will generally contain fewer harmful microbes.

“However, good oral hygiene doesn’t make saliva sharing risk-free. The mouth is never 100% sterile, and some decay-causing bacteria are always present,” Dr Sharif said.

She added that Streptococcus mutans can also team up with Candida albicans to create plaque that’s stickier and more acidic. “Its presence in a child’s mouth leads to a much higher risk of early childhood caries, and children with severe early decay often carry the same candida strain as their mother,” Dr Sharif said.

But dental health isn’t the only consideration. Dr. Amanda Furr, a board-certified paediatrician and chief medical officer at Zarminali Pediatrics, points out that viruses can also be transmitted through saliva, meaning common infections such as colds, flu and strep throat could potentially spread to a child before a caregiver even realises they’re sick.

“More severe infections like herpes simplex virus 1, or cold sores, can [also] be spread via saliva,” said Dr Furr, noting that a child’s first infection with this virus can cause extremely painful sores in the mouth and on the face. “In newborns, it can cause life-threatening meningitis, an infection around the brain.”

Experts agree that birth to about age three is the most vulnerable period for children when it comes to the potential health effects of saliva transfer.

“Newborns are particularly vulnerable to infection from saliva transfer,” said Dr. Leslie Treece, board-certified paediatrician at Cookeville Pediatric Associates, pointing to their underdeveloped immune systems.

“Possibly the most feared infection is the herpes virus from a kiss. This particular risk still exists past 30 days of age, but is much lower.”

The mutans bacteria, in particular, are a concern during these early years. “During this period is when new teeth are erupting, which gives the bacteria a fresh hard surface to attach to,” Dr Sharif said. “Since the child’s oral microbiome and immune system are still developing, the bacteria can cause damage faster.”

She added that once these microbes become established, they can be difficult to displace.

Dr Treece noted that by around age three, children typically have their own bacterial colonies established and better hygiene habits in place, which can help lower their risk. However, there are still periods when vulnerability may increase.

“There’s another window between ages six and 12 years, because their permanent teeth are erupting at that time,” said Dr Treece, adding that the risk is lower after age three. “The vulnerability changes as a child gets older. But is never really zero.”

Drinks get swapped, you mindlessly stick a spoon in your mouth to test your kid’s food, or maybe everybody shares a bite of dessert. “As a mother, I understand the realities of everyday family life,” Dr Furr said. “This is normal and cannot be prevented entirely.”

While an occasional instance of saliva transfer isn’t something to lose sleep over, there’s one situation where it’s best to be cautious.

“If someone is showing signs of illness or cold sores, any sharing of food or saliva exposure should be avoided to reduce exposure, especially in infants and newborns,” Dr Furr said.

She also recommended extra precautions, including avoiding kissing a baby on the face, covering coughs and washing hands frequently.

Sharing food often goes both ways: kids may take bites of a caregiver’s meal or sneak sips from their drink, too. While saliva transfer is one consideration, experts point out that there are other health and safety factors worth keeping in mind.

Beyond choking hazards, especially when a caregiver’s meal includes chunks of meat or nuts, there’s also the risk of foodborne illness. Dr Treece noted that children under age five are more vulnerable than adults.

“Young children have immature immune systems, and they can develop severe illness from food pathogens that an adult might tolerate with little to no symptoms,” she said, adding that this is especially worth considering with higher-risk foods, such as undercooked eggs, raw seafood, unpasteurised dairy, deli meats and bagged lettuce.

Allergen exposure is another potential concern. “If a child with known food allergies is sharing food with an adult, they can have a reaction to something the adult ate even a few hours earlier,” Dr Treece explained.

To prevent saliva transfer, Dr Sharif recommended testing your child’s food temperature on your skin. If you need to taste it, use a separate, clean spoon whenever possible. “If you’re sharing a spoon, you should run it under warm running water to reduce the risk of sharing saliva,” she said.

Dr Furr also recommended avoiding shared drinks when possible. “Keep baby bottles and pacifiers clean and carry extras. A caregiver should not put these objects in their mouth in an attempt to clean them,” she said, noting that soap and water should be used instead.