The FDA is investigating 35 cases of seizures that were reported after e-cigarette use.

Between 2010 and early 2019, there have been 35 reports of seizures after e-cigarette use to the FDA and to poison control centers across the country.

The Food and Drug Administration is investigating whether nicotine-induced seizures are a potential side effect of vaping.

In the past decade, the agency has received at least 35 reports of seizures — sudden and uncontrolled disturbances in the brain — following e-cigarette use. The cases were picked up by poison control centers across the country, and through the FDA’s adverse event reporting system, a database of voluntary reports from patients, product manufacturers, and health professionals.

“While 35 cases may not seem like much compared to the total number of people using e-cigarettes, we are nonetheless concerned by these reported cases,” FDA head Scott Gottlieb said in a Wednesday press release. “We also recognize that not all of the cases may be reported.”

The FDA says it’s too early to know for sure if the seizures were caused by the e-cigarettes since there was no clear pattern among the cases. While some involved first-time users and just a few puffs, others were experienced users. A few of the cases were people with a history of seizure diagnosis, and marijuana and amphetamine use.

The agency did not give the ages of the people, but it noted that “some people who use e-cigarettes, especially youth and young adults, are experiencing seizures following their use.”

The agency also wasn’t able to determine whether a particular brand or type of e-cigarette was most likely to be implicated, since many of the reports lacked that data. (Though it is notable that some devices, in particular Juul, deliver higher doses of nicotine.)

Yet researchers have long known that seizures can be a side effect of nicotine poisoning — affecting agricultural workers who handle tobacco leaves and toddlers who accidentally swallow e-cigarette liquid.

So the FDA is calling for more investigation into whether there is a connection, and asking doctors and the public to report cases to the federal “safety reporting portal.”

Michael Eriksen, the former director of the Centers for Disease Control and Prevention’s Office on Smoking and Health, put the potential risks in perspective. “It is 35 cases over 10 years. [That’s] three to five a year with millions of users. So [it’s a] one-in-a-million chance, while one out of two smokers die from smoking.”

Still, the warning adds to a growing body evidence that vaping may be riskier than we thought, especially for young people.

E-cigarettes may stress the cardiovascular system and lungs

When e-cigarettes appeared on store shelves a few years back, little was known about their health effects. But as more and more people use them, studies are piling up to suggest vaping might carry serious side effects for the heart, lungs, and developing brain.

As I’ve reported, there is growing concern that the nicotine and particles e-cigarettes emit could lead to long-term changes in heart rate and blood pressure, potentially increasing vapers’ risks of heart attacks, high blood pressure, and coronary artery disease.

Breathing vapor into the lungs can also irritate them, which has been demonstrated in recent research on wheezing. Wheezing — that high-pitched sound caused by narrowed and abnormal airways — is more than just an annoyance: It can be a sign of emphysema, heart failure, and lung cancer.

Researchers tracked 28,000 adults to tease out whether e-cigarettes exacerbate wheezing. Some of the people in the study were current vapers who used only e-cigarettes; others were smokers only; still others were dual users (who smoked and vaped); and finally, there were folks who didn’t smoke or vape at all. Compared with that last group, the non-users, the risk of wheezing among the vapers doubled.

“We have concerns about the direct effects of e-cigarettes on the airways,” Gottlieb said in his statement Wednesday. “This includes the potential for the use of such products to cause changes to airways that could be a precursor to cancer.”

Other studies have focused on whether e-cigarette users are more likely to develop chronic obstructive pulmonary disease (COPD), a set of lung complications that make it hard to breathe. Research in mice and human airway cells showed that nicotine-containing e-cigarette vapor seemed to trigger “effects normally associated with the development of COPD.” So the new, potential seizure risk is just the latest in a growing list of concerns.

As for the seizure risk, it’s possible that more investigation will find there’s actually no link, and that there’s some other factor that explains the cases already reported.

But, Eriksen warned, “In some ways, we are in uncharted areas when we talk about potentially inhaling large amounts of aerosolized nicotine.”