Hard as it may be to believe now but there was a time when cigarettes were sold almost as health products
http://indymotorspeedway.com/cigs/1930s.html
Tolkien was a great smoker and this was not regarded as anthing unusual. At the time the books were written the tobacco use would not have been remarkable. However to put a modern perspective on it Hobbits are "tough in the fibre" and like Numenoreans they don't seem prone to illness generally - premature deaths tend to be accidental.
But remember children, Elves don't smoke and they live forever and don't get wrinkles..... a lesson for us all?