Mithol

Many smokers do live to a ripe old age even these days. And if you take into consideration the fact that they probably smoked much less than your average modern-day smoker and that they smoked pipes, it isn't hard to believe that they could live so long. Anyway, Hobbits are not humans. They are a different race. Therefore their life expectancy is probs not based on their amazing healthy habits but instead on the amount of time it takes for their species' body to grow old and fail.