Casper LaVito, 69, says he has not smoked a cigarette in six months since he started vaping.

My dad reluctantly tried a Juul e-cigarette six months ago. He now likes it so much he won't give it up.

I bought my dad a Juul in November as an experiment to see if it would help him kick his longstanding cigarette habit. After a little over a week of vaping his Juul and smoking his Marlboros, he ditched the Marlboros altogether. He would text me every day to brag about how many days had passed since he smoked a cigarette.

This month, he celebrates six months without a cigarette, an achievement I frankly never thought I would see. The texts have stopped, but he still updates me on our Sunday night phone calls.

"It is such a relief to not be a smoker," said Casper LaVito, 69. "It's great. I can't believe it. I still can't believe it."

He typically vapes blueberry or strawberry knock-off Juul pods, as well as Juul's 3% strength mint pods. He said he has "no desire, no want, no care" to smoke a cigarette after 35 years of smoking, minus the few times he attempted to quit. He says he's even convinced friends to try Juul.

Dr. Stephen Gawne, my dad's primary care doctor at Edward Hines Jr. Veterans Administration Hospital, said he can't point conclusively to any medical data showing that switching to nicotine pods has helped improve my dad's health. However, he does say Juul helped him because it got him to stop smoking.

"Smoking cigarettes is the absolute worst as far as I'm concerned, so you gave him a great gift," he told me.

E-cigarettes may pose their own long-term health risks, the National Academies of Sciences, Engineering, and Medicine has concluded. They were first sold in the U.S. in 2003, so there are no studies of the health consequences of long-term use. But U.S. health officials say e-cigarettes are inherently less dangerous than cigarettes because they don't undergo combustion, the chemical process that occurs when tobacco burns and releases toxins.

That's why they're so hotly debated. On one hand, they could help adult smokers get their nicotine fix in a less harmful way. On the other hand, we don't know what happens when people use them for years.

"The best thing to do is to not do anything," said Belinda Borelli, a professor and director of behavioral science research at Boston University Henry M. Goldman School of Dental Medicine. "He's better doing Juul than combustible cigarettes, the question is for how long?"

I'm proud of my dad for quitting after more than three decades of smoking. To abstain from cigarettes for six months with no desire to go back, especially at his age, is a huge accomplishment. My only concern is that when I first gave him the Juul, he said he wanted to use it for a bit then wean eventually quit that, too. Not anymore.

"I'll stop using it, but I will always carry one, and if I have the urge, I gotta smoke," he said, adding that he likes his Juul more than anything.

He's vaping less today, one nicotine pod every two days, versus the one pod every day and a half. He also started using Juul's pods with less nicotine.

My dad highlights a key debate in the tobacco control community: whether e-cigarettes can help people quit nicotine altogether or whether they simply keep people hooked, albeit to a possibly less harmful product. To be clear, nicotine, while addictive, does not cause cancer, lung disease or any of the ill effects of smoking.

The Food and Drug Administration has taken the stance that nicotine products have varying degrees of risk: cigarettes are the most deadly and other products, including e-cigarettes and heated tobacco products, are less harmful.

"In the absence of combustion, we're going to have tough questions to ask ourselves as a society about nicotine and the so-called continuum of risk and the unintended consequences and the intended consequences," Mitch Zeller, who runs the FDA's Center for Tobacco Products, said at a recent e-cigarette forum.

Questions like if someone needs to stay on these products for a long time or forever, how do we feel about that? Especially like e-cigarettes that require a pulmonary delivery and can be more addictive," he said. "What if that's what it takes for a smoker to avoid relapse to the most harmful product, cigarettes?"

These are questions I'm grappling with now. My dad had been perpetually "quitting" for years, without ever actually quitting. At least now he's not smoking cigarettes, the deadliest way to consume nicotine. Yet I'm not sure whether he'll ever stop Juuling, and I don't know the consequences of that.

Ray Niaura, a professor of social and behavioral sciences at New York University, reassured me it's still early. From here, my dad could cut back or at one point maybe decide to give up his Juul altogether.

"First thing's first, get rid of smoking," he said. "Then you have more room to decide whether to get rid of the nicotine."

For now, I'll celebrate that my dad is finally cigarette-free.