[nightlight7]

Nicotine is just one medicinal component of tobacco smoke. For example, there are unknown components in the tobacco smoke which inhibit MAO B enzyme, the enzyme which breaks down dopamine and which normally increases as we age. As result of this effect of tobacco smoke (which is not due to nicotine) smokers in their fifties have MAO B levels of non-smokers in their twenties (see this thread which also debunks often parroted myths of antismoking pseudo-science). There are numerous other little publicized but scientifically well established beneficial effects of tobacco smoking.

[neverdem]

Thanks for the links.

[aruanan]

For example, there are unknown components in the tobacco smoke which inhibit MAO B enzyme, the enzyme which breaks down dopamine

There are compounds in broccoli that appear to do the same thing. On another note, I just attended a post-doc's presentation about certain mutations that can lead to the failure to break down dopamine, leading to endogenous dopamine toxicity, so it looks as though you can get screwed either way.