>>I doubt whether that is entirely true. Johan Cruif, Europe's best soccer player of the 20th century quit smoking about 20 years ago when he got a heart attack. He was a very heavy smoker up to his middle 40-ties. Guess what, he now got lung cancer. I find it a bit hard to believe his cancer is unrelated to his past.

>>I've got real problems with the 'evidence' of those research cases. In most cases it is way too thin. Since cancers are slow developing and often appear decades later, I do not hold much fate in such conclusions.

Fair enough- and you're right, on review I see it depends a lot on your age when you quit. Basically: smoking knocks ten years off your life. Quit before age 44 and you get 9 of those years back. Quit by 54 to get back 6 years, by 64 to get back 4 years. But quit before age 35 and statistically you get back all 10 years.

Also worth noting that lung cancer is not the only consequence of smoking. Most of the above comes from reduced risk of heart disease and stroke. But there's lots of other cancers as well as heart disease, vascular disease and plenty of consequences to diminish quality of life no matter how long you live.

And I agree that for people like Johan Cruif, it doesn't matter what his risk was: once you have the disease, for you it's a 100% issue, period.