How Safe Is It To Drink Tapioca Pearls in Bubble Tea?

In 2019, a story about a teenager who reportedly had more than 100 undigested bubble tea pearls in her abdomen went viral. 

Sounds scary, right? Well, it might not be as frightening as it seems. Healthcare providers are skeptical about whether this could happen.

According to the story, it all began when a 14-year-old girl from China told her parents she had been constipated for five days. She wasn't able to eat and had severe stomach pain. 

A CT scan revealed about 100 "unusual spherical shadows" in the girl's abdomen. Those spheres were undigested bubble tea pearls, her healthcare provider supposedly said. 

The girl claimed she drank only one bubble tea five days earlier, but her healthcare providers said she would have needed to consume much more than that to have those symptoms.

The story begs the question: Are bubble tea pearls safe to drink? Here's what you need to know about what's in the popular tea drink.

What, Exactly, Are Bubble Tea Pearls?

Bubble tea pearls, also called boba pearls or tapioca pearls, are usually made out of tapioca, a starch extracted from the roots of cassava plants. Water and sugar are often added to the tapioca to make the pearls gummy.

These pearls put the "bubble" in bubble tea, also known as pearl milk tea or boba milk tea. One cup of bubble tea can contain dozens of pearls.

And that's where things get interesting. According to healthcare providers who looked into the case of the teenager in China, tapioca and other ingredients typically found in bubble tea pearls wouldn't show up on an X-ray or CT scan. There had to be something unusual in the pearls the girl consumed for them to show on the scan.

Vladimir Kushnir, MD, a specialist in gastroenterology at Washington University Physicians in St. Louis, Mo., told Health that an indigestible additive may have been in the pearls. Still, it wasn't clear what kind of additive that would be.

To make matters even more interesting, a 2017 case study published in the Journal of Acute Medicine reported pearl-like spots showing up on a CT scan of an 18-year-old. The spots were six to eight millimeters in size, consistent with the size of bubble tea pearls. 

The study suspected those spots appeared in the teenager's stomach and the first part of the small intestine (called the duodenum) because the girl had consumed the bubble tea earlier that day.

How Safe Are Bubble Tea Pearls?

For all of you bubble tea fans, don't worry. The odds are low of developing constipation and pain from your tea drink. 

However, Dr. Kushnir said that an additive sometimes used in bubble tea pearls, called guar gum, can cause constipation. Guar gum is a fiber that helps hold the balls together. The fiber expands when it comes in contact with water. Some people can use guar gum to treat digestive issues. Still, when consumed in high amounts, and with insufficient water, it can lead to constipation.

And there's even good news. The bubble tea pearls may even have some health perks, at least for your oral health. 

A study published in F1000 Research in 2021 found that bubble tea pearls could improve the quality of your saliva. Specifically, the researchers found lower levels of CRP, a protein linked to inflammation, in the saliva of people who drank bubble tea for three days.

But here's the caveat: Bubble teas can be high in sugar and calories. In fact, just one 16-ounce bubble tea has more added sugar than what is recommended by the 2015 US Dietary Guidelines Advisory Committee, according to a 2016 article published in Food Science & Nutrition. So, people who drink them can be at higher risk of developing obesity and diabetes.

A Quick Review

So, the tapioca pearls in bubble tea are generally safe to drink. But there are a few reasons to enjoy this sweetened beverage in moderation. Drinking too much of it may increase your chances of developing diet-related diseases and leave you constipated. 

"One to two cups a day should be fine, but you shouldn't consume anything in excess," advised Dr. Kushnir. "If you're drinking five or six cups a day, and you're noticing a change in your bowels, it could be a sign that you need to cut back or drink more water."