You might think that deciding what causes cancer, and what does not, is something that's not up for debate. Either a chemical causes cancer – or it doesn’t. Chemicals which cause cancer, such as the benzine and polonium-210 that you'll find in a cigarette are carcinogens. Chemicals which DO NOT cause cancer, such as nicotine, are not carcinogens. Up until now, that is.

The International Agency for Research on Cancer (IARC) plans to review nicotine, and they're considering classifying nicotine as a carcinogen. Not because it causes cancer, but because there's some inconclusive evidence that it might promote existing tumor growth. Which is actually a bit ironic, since the IARC has this posted on their website:

Does nicotine cause cancer? No. Nicotine is a common chemical compound found in tobacco plants, and its effect is to make tobacco addictive rather than to cause cancer directly. People who are addicted are more likely to continue to expose themselves to the carcinogens in smoked or smokeless tobacco.

Cancer Causing vs. Tumor Promoter

The difference between something that causes cancer and something that (allegedly) worsens an existing tumor is an important one. We have perfectly usable words to describe each: carcinogen and tumor promoter. Ordinary people won't benefit from a blurring of the definitions, although I can think of a number of large industries that certainly will.

The semantics are important. If nicotine is classified as a carcinogen, then e-cigarettes will become even more tightly regulated. The existing FDA regulations for vaping are harsh enough — and there's almost no evidence to support them! If they're able to finesse nicotine into a carcinogen, I can imagine that an outright ban on e-cigs is a real possibility.

As of now, there is no clear evidence that nicotine itself is harmful. In fact, it could actually be helpful in treating various conditions.

So Is Nicotine Dangerous or Not?

Scientists are split on nicotine. Many scientists (and most vapers) believe that nicotine is a relatively harmless drug similar to caffeine. They think nicotine may even have some health benefits, such as protection against Alzheimer's and Parkinson’s, and see nicotine replacement therapy as a valuable quit-smoking tool. The FDA knows from decades of research that nicotine replacement products “do not appear to have significant potential for abuse or dependence.”

The critics believe that nicotine is far from benign. They point to studies which show that it may be harmful to pregnant women or the adolescent brain. For the critics, being able to claim that nicotine is a carcinogen would be a major PR victory. Nicotine won't suddenly gain any cancer-causing properties because of the classification change, but the public might think so…

In the end, we simply don't know enough about nicotine because almost every study that has looked at nicotine has either evaluated smoking – or smokers. Cigarettes contain a cocktail of 7,000 chemicals, many of which are proven carcinogens. Nicotine IS NOT! And even though smoking is addictive, it could very well be the case that nicotine is less addictive when used in isolation. When was the last time you saw someone with a nicotine patch addiction?

Not All Bad News…

There's still a chance of a good outcome for vapers, though. The IARC could clear nicotine, just as it recently cleared coffee. Simon Chapman, a well-known e-cigarette skeptic, has even said that if the IARC clears nicotine, “it'll be good enough” for him. But will it be good enough for everyone else?

Probably not, but we'll certainly keep an eye out for the IARC's findings. It plans to review nicotine between now and 2019.