Ted, 
 
Thanks for the question. 
 
I would make the analogy that our modern-day Word of Wisdom is similar to God's commandments to people in the Old Testament where they had many laws/commandments tied in with Mosaic law. God gives some commandments to His children here on earth in the context of the time and situation in which they are living. In Moses day part of the reason for some of the laws was to address some health concerns in their day. This is similar to us in our day where Heavenly Father is kind enough to us to warn us of things that can be harmful to our health and families. I don't think there is any question that smoking is harmful to one's health. I also don't think there is any question of the powerful societal impact that alcohol abuse has on individuals and families. Personally I am grateful to a Heavenly Father who is so concerned about us that he provides counsel for us that if we will obey it that we can be in some respects shielded from the harmful effects of them. 
 
Hope that helps give some perspective.