National Academy of Sciences Report on Electronic Cigarettes Confirms that Vaping is Much Safer than Smoking and Has No Known Long-Term Health Effects

My commentary on the conclusions and implications of the National Academy of Sciences report on electronic cigarettes was just accepted as an op-ed piece in U.S. News & World Report. I expect it to be published tomorrow. For this reason, I have had to take down the original commentary. However, below I have posted the parts of the original blog post that had to be cut from the op-ed because of length concerns. Also, I will post a link to the op-ed as soon as it appears.

The key findings of the report are:

1. "There is substantial evidence that except for nicotine, under typical conditions of use, exposure to potentially toxic substances from e-cigarettes is significantly lower compared with combustible tobacco cigarettes."

2. "There is conclusive evidence that completely substituting e-cigarettes for combustible tobacco cigarettes reduces users’ exposure to numerous toxicants and carcinogens present in combustible tobacco cigarettes."

3. "There is moderate evidence that risk and severity of dependence are lower for e-cigarettes than combustible tobacco cigarettes."

4. "There is moderate evidence that second-hand exposure to nicotine and particulates is lower from e-cigarettes compared with combustible tobacco cigarettes."

5. "There is no available evidence whether or not e-cigarette use is associated with clinical cardiovascular outcomes (coronary heart disease, stroke, and peripheral artery disease) and subclinical atherosclerosis (carotid intima media-thickness and coronary artery calcification)."

6. "There is insufficient evidence that e-cigarette use is associated with long-term changes in heart rate, blood pressure, and cardiac geometry and function."

7. "There is no available evidence whether or not e-cigarette use is associated with intermediate cancer endpoints in humans. This holds true for comparisons of e-cigarette use compared with combustible tobacco cigarettes and e-cigarette use compared with no use of tobacco products."

8. "There is no available evidence whether or not e-cigarettes cause respiratory diseases in humans."

9. "There is limited evidence for improvement in lung function and respiratory symptoms among adult smokers with asthma who switch to e-cigarettes completely or in part (dual use)."

10. "There is limited evidence for reduction of chronic obstructive pulmonary disease (COPD) exacerbations among adult smokers with COPD who switch to e-cigarettes completely or in part (dual use)."

11. "While the overall evidence from observational trials is mixed, there is moderate evidence from observational studies that more frequent use of e-cigarettes is associated with increased likelihood of cessation."

12. "There is substantial evidence that e-cigarette use increases risk of ever using combustible tobacco cigarettes among youth and young adults."

13. "There is conclusive evidence that, other than nicotine, the number, quantity, and characteristics of potentially toxic substances emitted from e-cigarettes is highly variable and depends on product characteristics (including device and e-liquid characteristics) and how the device is operated."

The Rest of the Story

I agree with all of the above conclusions, other than #12, which is not wrong on its face but needs careful interpretation.

Therefore, let me say a few words about conclusion #12 above ("There is substantial evidence that e-cigarette use increases risk of ever using combustible tobacco cigarettes among youth and young adults"). It is true that youth who experiment with e-cigarettes are more likely to also experiment with tobacco cigarettes and therefore, to become smokers. It would be shocking if this were not the case because we know that youth who experiment with one risky behavior are more likely to experiment with other risky behaviors. But this doesn't necessarily mean that the experimentation with e-cigarettes is causing the youth to start smoking.

For example, there probably are not many kids who use heroin who have never taken a sip of alcohol. If you did a study, you would find that alcohol use is associated with later use of heroin. But this doesn't support the conclusion that experimenting with alcohol causes kids to become heroin junkies. It simply reflects the fact that kids who take huge health risks are more likely to already have taken smaller health risks. A youth is not going to decide to rebel one day by injecting a drug into their veins. The rebellion process would likely start with a less hazardous behavior, such as taking a toke on a cigarette and then for a very small number of kids, they would end up progressing to hard drug use.

So the important question is not whether youth who experiment with e-cigarettes are more likely to end up smoking (of course they are!), but instead, whether youth who experiment with e-cigarettes are more likely to become addicted to vaping and then be led to smoking addiction, such that without having become addicted to vaping, they unlikely would have become smokers. So far, the evidence suggests that this is not the case: very few youth have been identified who started as nonsmokers, became regular vapers, and then progressed to smoking.