Similar way as coffee does.
Tobacco use has some good health effects - lowers the stress, is corelated with delay or smaller chance for Parkisnon and Altzheimer. Moderate smokers who do not inhale (pipe or cigar smokers) can live on average a little longer than non-smokers. If so they are the real culprits - they costs society more by dying later.
That's my secret to staying there: coffee, ginseng. =]