These researchers swallowed Legos for science | Science News for Students

These researchers swallowed Legos for science

The toys should pass through the digestive tract without harm, study concludes
Feb 8, 2019 — 6:45 am EST
a photo of four different Lego minifigures lying on their backs in a circle, heads towards the middle of the photo

Would you eat one of these for science? Six doctors did. 


Legos are always up for travel. Sometimes, they head all the way to space, as in The Lego Movie 2: The Second Part. More often, Legos voyage through the homes and yards of the kids that play with them. But sometimes, they travel into the kids themselves. But parents shouldn’t worry. Legos go right through the body in just a few days. A group of physicians confirmed that. They swallowed Legos — and checked their poop to confirm the toys made a successful journey.

It’s not too surprising that a kid might end up snacking on a random Lego brick or two. The toys are tiny and candy-colored. When a child eats a brick, though, parents rush to the hospital, terrified that their kid may suffer a Lego-induced demise. Tessa Davis can calm their fears. She is an emergency pediatrician — someone who treats medical emergencies in children — at Royal London Hospital in England. She’s one of the physicians who downed a Lego — for science, of course.

When Legos are this candy-colored, they do look awfully tasty.
Warner Bros. Pictures/YouTube

“It’s actually really common,” Davis says. “We see at least one child a day swallowing something they shouldn’t have.” The most common swallowed items are coins, she says. But anything left lying around — such as a Lego — is in danger. Most of the time, unless the object is sharp or toxic (such as a battery), it will just go right through the child and come out the other end.

No matter how much Davis has tried to reassure parents, though, they kept worrying. So she and five other doctors decided to do the ultimate test. They each swallowed the head of a Lego figure. Why a Lego head? “Lego heads are a standard size,” she says. The doctors wanted to make sure they ate the same thing.

“We all swallowed one at the same time of day and then waited to see if it came out,” she says. Without chewing or seasoning, the doctors gulped the toy parts down like pills.

Then they waited. Each doctor kept a poop diary. They tracked how often they pooped and how hard their feces were when the toy eventually came out. Everyone took care to eat a normal diet. (“Corn would have just confused the results,” Davis notes.) Then the doctors collected their poop and hunted for a familiar-looking yellow smiley face.

That meant digging through their own poo. “Everyone used different techniques, chopsticks, forks,” Davis says. “Some people put it into Ziploc bags and squished it around. Just finding [the toy] was important.” Dedication to science is one thing, but Davis admits that poking through her poop wasn’t “the most pleasant few days of my life.”

Luckily, the doctors didn’t have to dig through too much doo-doo. Of the six Lego heads that went in, five came out again within three days. One doctor, however, never found his Lego head. “Most likely he wasn’t good at looking [for it],” Davis concludes. “But it’s possible in 10 years’ time someone will find it up there.” Davis and her dedicated poop-poking colleagues published their findings November 22, 2018 in the Journal of Pediatrics and Child Health.

“Every parent has that moment when their child could have swallowed something and they panic,” notes Brian Crandall. He leads science activities for elementary-school kids at Mad Science of the Mid-Hudson in Goshen, N.Y. Crandall also knows about swallowing things for science. He was involved in a study where a scientist swallowed a whole shrew, just to find out if ancient humans could have eaten the small animals. Crandall will neither confirm nor deny that he was the scientist who swallowed the shrew, but he notes, “I’m a little envious of the Lego heads. Come on, that’s easy. Swallowing meat that you’re not used to eating is a lot more challenging.”

It may not be a shrew, but Crandall notes that the Lego head study is very reassuring. “I’ve printed out a copy,” he says. “Children are such amazing creatures. No matter how many times an adult can say to a group of children, ‘please don’t put that in [your] mouth,’ there’s a certain percentage that are just going to put it in their mouths. And now’s there’s a study saying it’ll go through.”

Davis uses the study in the hospital, as well. “I keep a Lego head on my hospital bag and show them” — to calm their fears, she says. (Don’t worry, it’s not a Lego head from the study.) After all, now she has science on her side.

Power Words

(more about Power Words)

battery     A device that can convert chemical energy into electrical energy.

colleague     Someone who works with another; a co-worker or team member.

diet     The foods and liquids ingested by an animal to provide the nutrition it needs to grow and maintain health. (verb) To adopt a specific food-intake plan for the purpose of controlling body weight.

feces     A body's solid waste, made up of undigested food, bacteria and water. The feces of larger animals are sometimes also called dung.

journal     (in science) A publication in which scientists share their research findings with experts (and sometimes even the public). Some journals publish papers from all fields of science, technology, engineering and math, while others are specific to a single subject. The best journals are peer-reviewed: They send all submitted articles to outside experts to be read and critiqued. The goal, here, is to prevent the publication of mistakes, fraud or sloppy work.

pediatrician     A field of medicine that has to do with children and especially child health. A doctor who works in this field is known as a pediatrician.

pediatrics     A field of medicine that has to do with children and especially child health. A doctor who works in this field is known as a pediatrician.

plastic     Any of a series of materials that are easily deformable; or synthetic materials that have been made from polymers (long strings of some building-block molecule) that tend to be lightweight, inexpensive and resistant to degradation.

shrew     A mouse-sized, insect-eating mammal. Related to moles, it’s chiefly active at night. It has a long, pointed snout and tiny eyes. Despite looking somewhat mouse-like, a shrew is not a rodent (which a mouse is).

toxic     Poisonous or able to harm or kill cells, tissues or whole organisms. The measure of risk posed by such a poison is its toxicity.


Journal: A. Tagg et al. Everything is awesome: Don't forget the Lego. Journal of Paediatrics and Child Health. Published online November 22, 2018. doi: