Sorry, it is nothing personal, as far as I'm concerned if it legal like smoking and drinking, you do what you want to do., If people are informed objectively (which in the case the PC brigade and sensational press doesn't happen) then do what you are comfortable with. IMHO a human body can take so much in toxins, smoking, drinking, food, exercise levels and sleep are the basic parameters and you can pull it in the direction you personally choose. As far as I'm selfishly concerned I would make everybody pay into a big national pension pot, and encourage everybody to smoke at least 60 cigarettes a day, drink a minimum of 20 pints or a bottle of spirits a day, eat rubbish junk food, no exercise in any way and party every day so they rarely sleep. My retirement pension would then be fantastic.

All I can tell you about is that smoking did not do my great uncle any good at all, he had a terrible short life, he smoked cigarettes like 98% of men, during WWI and moved on to cigars. At 80 when he was fitter than most 50 year olds, he and his wife moved to the Colorado in the USA, where his daughter had settled after marrying an American during WWII and as a chippie he turned his daughters basement into a 'granny annex' - his words. In his mid-eighties he could no longer afford the health insurance, so he came back to the UK, cigars in the UK were expensive and cheap in USA so he used his chippy skills to maximum convenience, all his packing cases had a good layer of cigars below a false floor! Once he was back in the UK between 85-90 he completely transformed a rundown rented house, but his health really caught up with him in his 90's...... arthritis, but as a smoker the grim reaper unfortunately caught up with him at last at 98, a life cut so short through smoking.

He was always my favorite uncle, party because one of my major hobbies has always been woodwork, but mainly because he inspired me, that if you work hard every day and keep fit, then with any luck you will live to a good age along with having a few vices, this is still what I follow today and hope as a result to reach 98?!
I don't smoke and rarely gamble, eat a healthy diet but I have a few vices like most people, I enjoy my food, so I'm a bit over weight, I enjoy a good drink and I have a keen eye for pretty women.

, so about 50% of good-bad vices is in IMHO about right.
But (don't we all hate it when some smart ass (this time me) uses these 3 letters) research has shown that smoking or passive smoking increases type 2 diabetes by about a factor of 2