Every few months, a new study about the effects of smoking e-cigarettes concludes the opposite of whatever came before it. It’s a cycle that started when the popularity for the cigarette alternatives exploded a few years ago and has led to a lot of confusion over whether vaping is bad for your health.

We have, over the decades, mostly come to a consensus on the dangers of smoking combustible cigarettes—a conclusion founded on countless long-term studies. Until now, e-cigarette studies have simply either analyzed the product or investigated the effects on animal and cell models.

A new study funded by Cancer Research UK is the first to explore the effects of e-cigarettes by looking at long-term human body-level exposure. The results are promising.

The study looked at five groups: combustible cigarette users, former smokers who now smoke e-cigs, former smokers on nicotine replacement therapy (NRT), and current smokers who also smoke e-cigs or also use NRT.

The study concluded that e-cigarette-only and NRT-only users had significantly lower levels of carcinogens than combustible cigarette-only, smokers of both cigarettes and e-cigs, and smokers of cigarettes who are also NRT users.

After analyzing the urine and saliva of 181 participants, researchers found that levels of NNAL, a chemical linked to cancer, was 97.5 percent lower in ex-smokers who vape compared to continuous smokers.

“The take-home message for smokers and e-cigarette users is that using e-cigarettes long-term is likely to carry substantial health benefits, certainly in relation to cancer risk, compared with continued smoking. E-cigarettes are certainly safer than combustible cigarettes,” Lion Shahab, one of the scientists working on the study, told Digital Trends.

Cancer isn’t the only risk when smoking cigarettes. Shahab says the next test will need to look at smokers over a longer period of time to determine their respiratory and cardiovascular health.

Until that happens, e-cigarette smokers can worry more about their devices exploding than anything else.

H/T Digital Trends