New Study Tests Bubble Tea for Hidden Danger

Testing of bubble tea by Consumer Reports found that levels of lead are slightly higher.

Published: 10/23/2025, 2:44:58 PM EDT

New Study Tests Bubble Tea for Hidden Danger — Hong Kong Street Cart’s bubble teas. (Erin Kestenbaum)

With the number of bubble tea shops increasing every year, so are concerns about lead poisoning.

The market research group IbisWorld estimates that in 2024, there were 6,635 bubble tea shops across the country, and that number is expected to double by 2028.

Tapioca-based pudding balls, known as boba pearls, combined with a mixture of brewed tea and dairy, differentiate bubble tea from traditional tea sold at coffee shops such as Dunkin' Donuts.

Lead poisoning concerns center around tapioca, which is extracted from the starchy root vegetable cassava.

Also known as yuca or arrowroot, AllRecipes.com describes cassava as being similar to sweet potato or yam but with a thicker outer layer and gluten-free.

However, a Consumer Reports (CR) study found that food made with cassava, such as chips and bread, can potentially contain high levels of lead, and the presence of lead in food items can potentially cause poisoning.

The Mayo Clinic describes lead poisoning as a buildup in the body from small amounts of lead consumed over time that can result in serious health problems and, in some cases even death.

Out of 27 cassava food items, two-thirds contained more lead than experts advised is appropriate to eat in one 24 hour period, according to CR testing.

As a result, CR said it separately tested tapioca pudding balls for levels of arsenic, cadmium, lead, and mercury in bubble tea sold at the Gong Cha and Kung Fu Tea retail stores in New York, Massachusetts, New Jersey, Texas, and Pennsylvania, as well as in do-it-yourself pudding ball kits sold at Trader Joe’s and in WuFuYuan on Amazon.

The CR bubble tea study found that lead levels are slightly higher.

“These levels weren’t so high that we’d tell people to completely avoid bubble tea,” CR food safety research and testing director James Rogers said.

However, CR does recommend viewing drinking bubble tea as a non-essential indulgence.

“While this wasn’t a comprehensive look at the boba and bubble tea market, the fact that three out of the four boba samples contained more than 50 percent of our level of concern for lead in one serving is a good reason to treat it as an occasional treat, not an everyday staple,” Rogers added.

Symptoms of lead poisoning include developmental delays, learning difficulties, irritability, loss of appetite, weight loss, sluggishness and fatigue, abdominal pain, vomiting, constipation, hearing loss, and seizures, according to the Mayo Clinic

"The very young are particularly vulnerable to the potential harmful effects from lead exposure because of their smaller body sizes and rapid metabolism and growth," the FDA states on its website. "For adults, chronic lead exposure is associated with kidney dysfunction, hypertension, and neurocognitive effects."