See my previous blog entry about how I taught the Word of Wisdom lesson in Relief Society.
When I was a TBM, I believed that the Word of Wisdom (as explained in D&C 89) was proof of Joseph Smith's prophetic calling. After all, he revealed that tobacco and alcohol were detrimental to human health nearly 120+ years before scientific research was able to document the negative effects of smoking and alcoholism. I saw this as clear evidence that he was a true visionary.
While I think that avoiding tobacco and alcohol is ultimately a good thing, I no longer believe that the Word of Wisdom is a revelation from God. In this blog entry, I'll explain some of the reasons why my attitudes toward the Word of Wisdom have shifted.
The Word of Wisdom Didn't Mean the Same Thing in 1833 as It Does Today
One of my current pet peeves is whenever I hear someone say that "the church has always been the same yesterday, today, and forever" or something to that effect. Such statements are demonstrably false. The doctrinal evolution of the Word of Wisdom is a perfect refutation of that misconception.
Check out this awesome quote by Brigham Young delivered as part of his sermon in the Old Tabernacle on March 10,1861:
Many of the brethren chew tobacco, and I have advised them to be modest about it. Do not take out a whole plug of tobacco in meeting before the eyes of the congregation, and cut off a long slice and put it in your mouth, to the annoyance of everybody around. Do not glory in this disgraceful practice. If you must use tobacco, put a small portion in your mouth when no person sees you, and be careful that no one sees you chew it. I do not charge you with sin. You have the "Word of Wisdom." Read it. Some say, "Oh, as I do in private, so do I in public, and I am not ashamed of it." It is, at least, disgraceful. ... Some men will go into a clean and beautifully-furnished parlour with tobacco in their mouths, and feel, "I ask no odds." I would advise such men to be more modest, and not spit upon the carpets and furniture, but step to the door, and be careful not to let any person see you spit; or, what is better, omit chewing until you have an opportunity to do so without offending. ... We request all addicted to this practice, to omit it while in this house [the tabernacle]. Elders of Israel, if you must chew tobacco, omit it while in meeting, and when you leave, you can take a double portion, if you wish to. 
Let's take a look at another awesome quote---this time from Joseph Smith. Following a wedding which took place in 1836 (yes, that's after the Word of Wisdom was first published), Joseph Smith recorded in his diary: "We then partook of some refreshments, and our hearts were made glad with the fruit of the vine. This is according to the pattern set by the Savior Himself, and we feel disposed to patronize all the institutions of heaven." 
I don't think these quotes are evidence of hypocrisy on the part of the early church leaders. Rather, I think it's clear that the church's interpretation of the Word of Wisdom has changed dramatically since it was first revealed in the 1830s. It's not entirely certain how the early saints interpreted the Word of Wisdom but some historians have proposed some interesting theories. 
Although D&C 89 states that the Word of Wisdom is not sent "by commandment or restraint," later church leaders perhaps thought it should have been. The shift in the interpretation of the Word of Wisdom can be traced to the presidencies of Joseph F. Smith (president from 1901 to 1918) and Heber J. Grant (president from 1918 to 1945). Smith and Grant heavily emphasized a strict proscription of alcohol, tobacco, tea and coffee. They began to encourage bishops and stake presidents to deny temple recommends to those who did not keep their version of the Word of Wisdom (with some leeway for older members who had not grown up with these standards).
What I think is interesting to note is that Smith's and Grant's stricter interpretation of the Word of Wisdom coincides with the rise of the Prohibition movement in larger American culture. So these early church leaders may have been heavily influenced by larger social and political movements.
I think faithful members have an "out" by saying that our understanding of the Word of Wisdom has been refined by continuing prophetic revelation. I think that's a fair statement, but the discrepancy between how the early saints lived the Word of Wisdom vs. how contemporary saints interpret it does open up a space for an interesting dialogue about our understanding of it.
What's So Bad about Moderate Alcohol and Tea Consumption Anyway?
I personally don't like the smell of coffee and I think it's fairly healthy to reduce one's caffeine consumption. However, it's difficult to say that it is healthy to avoid teas, especially green tea (which is not an herbal tea and is therefore forbidden by the Word of Wisdom). Just a quick Google search for "health benefits of green tea" should be enough to show that there is a medical consensus that green tea is good for you. According to a blog entry on WebMD (which begins by saying "It's difficult not to gush about green tea"), it has the potential to fight cancer and heart disease. It can also possibly lower cholesterol, burn fat, and it can possibly prevent diabetes, stroke, and dementia.
The same gray areas exist when it comes to the health benefits of alcohol. While drunkenness has obvious moral implications and prolonged alcoholism can certainly be detrimental to your health, drinking wine in moderation (e.g. a small glass a day) has been proven to be beneficial to your health. According to this blog entry on Health.com, a glass of wine a day can help prevent ovarian cancer, improve your memory, help you lose weight, boost your immune system, and help prevent bone loss and type 2 diabetes. The health benefits for women in particular are striking.
For that matter, an economic study in 2006 showed that teetotalers make significantly less money than their drinking counterparts. Alcohol has always been a well-known social lubricant and employees who regularly hang out in bars with their co-workers, customers and friends have been shown to increase their social capital. As the story I linked to states, drinkers "find out more about what the competition's up to, how they solve their problems, and more about new job opportunities. All that can lead to increased financial capital in the form of higher wages."
At the very least, all of this is interesting food for thought.
And Here's What the Law of Health Should Have Been...
As I mentioned earlier in this blog, I used to think the Word of Wisdom was one of the best proofs of Joseph Smith's prophetic guidance. I feel differently now. I'm going to pull a William E. McLellin and write some verses that should have been in the Word of Wisdom:
Behold, verily, thus saith the Lord unto you: In consequence of your lack of knowledge about germ theory, I would exhort you to wash your hands with soap and hot water. Yea, before eating your meals and after expelling your excrement, you must always remember to wash your hands. Remember, remember that I the Lord hath commanded it.
Yea, let all your water be boiled for 3 to 5 minutes before drinking or using it. For it is pleasing unto me to stop the spread of infectious diseases among my people.
And again, if you ever settle near a swampy area in Illinois, take care to drain any nearby swamps, for standing water is a fertile breeding ground for mosquitoes in all their varieties. Mosquitoes are unclean to me, for they do carry malaria and all sorts of infectious diseases that inflict and torment man.
And again, build outhouses that are at least six feet deep or more so that you may better manage your waste and thereby avoid dysentery and the dreaded hookworm. When an outhouse becomes over full, take care to bury this waste deep in the ground.
Yea, if there be any among you who fall ill, let them be quarantined and remain in isolation, with contact only from one or two caregivers to care for them in their sickness. And let those who care for them cover their hands, nose and mouth at all times lest they fall ill as well.
All saints who remember to keep and do these sayings, walking in obedience to these commandments, shall have their life expectancy increased and their infant mortality rate reduced. Thus saith the Lord. Amen.
Although living the Word of Wisdom can have a significant impact on the prevention of chronic diseases that develop in adulthood (such as heart disease and cancer), most of the early saints never lived long enough to enjoy these health benefits. That's because they died too early from infectious diseases such as infant diarrhea, dysentery, diphtheria, scarlet fever, typhoid, tuberculosis, cholera, malaria, yellow fever and smallpox. I personally think that a more practical health system (such as the one I suggested above) would be much better proof of the Word of Wisdom as a divine law of health. Then it truly would have been ahead of its time. But, hey, that's just me.
 See the chapter entitled "The Fraternity of Mormon Scholars" in Leonard Arrington's Adventures of a Church Historian where this quote appears. The chapter "Our First Publications" also contains several other juicy tidbits from Brigham Young about his own tobacco use.
 See History of the Church of Jesus Christ of Latter-day Saints, edited by B.H. Roberts, 2nd ed., 2:369.
 See Lester Bush's "The Word of Wisdom in Early Nineteenth-Century Perspective," from Dialogue 14.3 (Aug. 1981) for a discussion of how the Word of Wisdom was consistent with popular medical beliefs at the time. I also highly recommend Clyde Ford's "The Origins of the Word of Wisdom" from The Journal of Mormon History 24.2 (Fall 1998) for a fascinating discussion of how the Word of Wisdom may actually be the compilation of three separate revelations with three different purposes.