If you’ve been to a mall lately, chances are you’ve seen e-cigarettes being sold at a kiosk. Instead of producing smoke, battery-operated e-cigarettes (which have been growing in popularity since they were introduced in 2005) turn a nicotine-filled liquid into a vapor that’s inhaled or “vaped.”

So using e-cigarettes is often marketed as the “safe” way to smoke and as a healthy way to wean yourself off actual cigarettes—but is it?

A new study is the first to call that common claim into question.


There has been very little research to date on the safety of e-cigarettes, yet they’re still allowed to be sold because they’re categorized as “tobacco products,” as opposed to “drug delivery” devices. So researchers at the Center for Global Tobacco Control at the Harvard School of Public Health in Boston were eager to get some answers. The study goal was to see whether using an e-cigarette for just five minutes, the average amount of time it takes a person to smoke one regular cigarette, would impact lung health. Results were published online in the medical journal Chest. To learn more, I called Constantine Vardavas, MD, RN, MPH, PhD, a scientist at the Center and the study’s lead author.

How the study worked: Participants included 30 male and female smokers, ages 19 to 56. Researchers tested participants’ lung function and then asked them to “vape” from an e-cigarette for five minutes, and during that five-minute period the researchers retested each subject’s lung function.

The results: Researchers discovered that five minutes of vaping increased airway constriction in the lungs by 18%, on average. This result was too small to lead to shortness of breath or breathing difficulties, but the concern is that more frequent or prolonged vaping could potentially lead to those health problems. Even more worrisome, said Dr. Vardavas, was the second finding—use of the e-cigarettes reduced the amount of nitric oxide that was exhaled (by 16%), and that is an indication of inflammation in the lungs.

All after just five minutes!

The study did not examine how long the participants’ lungs suffered these effects, Dr. Varadavas said. He suspects that airway constriction likely improved and that inflammation likely subsided relatively quickly. But, he wondered, what if someone “smokes” an e-cigarette multiple times a day, day after day? Would the lungs be able to bounce back as quickly…or at all? The truth is, no one knows, but we do now know that e-cigarettes are not entirely harmless.


The FDA is not ignoring the e-cigarette health question. Back in 2010, the FDA tried to categorize them as drug-delivery devices. This would have compelled manufacturers to prove that that the devices are safe and effective at helping people quit smoking. But a US Court of Appeals blocked the FDA’s attempt because the court didn’t agree with the categorization, so manufacturers never had to do any of that.

Supporters of e-cigarettes argue that any toxins in e-cigarettes are present in very small amounts and are found in other FDA-approved products, such as nicotine patches and nicotine gum. They add that the FDA has yet to provide any proof that these contents cause harm. And there is at least one small study that has shown that e-cigarettes may help people quit smoking. The gist of the argument for e-cigarettes, if I may paraphrase, is that e-cigarettes might harm you a little bit, but real cigarettes are much, much more harmful.

That may be. But “vape” with caution—they aren’t harmless.