Smoking seems to cause lung cancer in some people but we don't know what would happen to those people if they didn't smoke. It's likely in some people smoking h

Smoking seems to cause lung cancer in some people but we don't know what would happen to those people if they didn't smoke. It's likely in some people smoking happens with other habits that would cause one issue or another but in other people it's not that. The studies that try to generalize smoking to life expectancy seem questionable.