>does that mean you can smoke with no health consequences by stopping when you're middle aged? The answer to that is clearly no. Young people aren't immune to

>does that mean you can smoke with no health consequences by stopping when you're middle aged? The answer to that is clearly no. Young people aren't immune to cancer; they're also increasing their risk of developing cancer while they smoke... Additionally, this study only speaks of lung health. There is also lots of evidence out there showing smoking adversely affects cardiovascular health... whether you heal from those effects is another matter. On a personal anecdote, both my grandfathers smoked their entire lives - and both had thoracic aortic aneurysms (one actually had his rupture and survived miraculously despite a 97-99% mortality rate). Anyhow, tobacco use is a risk factor for developing thoracic aneurysms - and I can't see how one's aorta would ever go completely back to normal after developing such a malformation...