First off, let me say that this post isn't about whether masturbation is healthy...
The post cites an article that was just published that looked into the the association between masturbation in early adulthood and risk for prostate cancer. Now, the study showed an increased risk of developing prostate cancer early for those who masturbated most frequently in their 20's, but even in their own discussion admit that the high level of hormones leading to the increased risk may well be the reason for the higher levels of sexual activity (masturbation or intercourse). Thus, the high levels of testosterone are causing both the frequent masturbation in the 20's and early onset of prostate cancer.
One thing they showed is that masturbation in later years tends to serve as a protection from cancer, presumably from clearing the prostate of carcinogens by ejaculation. This protective affect has been shown in other studies as well. In the linked study (much larger too: 800 men in the one finding masturbation to increase risk; 29,000 in the one finding it to decrease it), the effect was shown to be true even for younger men (20's).
But as I said, that's not the point. Sure, I believe that medical science has almost completely redeemed masturbation from the disease/insanity/imbecilism-causing activity it used to be seen as. Rather, my question here is: Why do we LDS feel that in the commandments must be temporal in nature. In D&C 29, the Lord tells us that His commandments are all spiritual, not carnal, not temporal.
If masturbation is wrong morally, what does that have to do with the physical. The act could easily be inappropriate morally without having adverse health consequences. But Mormons seem to love the idea that all the commandments have direct temporal reasons for their existence.
It's like having a conversation about the health benefits of drinking a glass of red wine at dinner, or the health benefits that can be derived from drinking tea. Mormons (ok, so that's a blanket statement, and probably shouldn't be, but let's read that as, "many of the Mormons I've come in contact with") tend to think the scientists are wrong, or trying to appease their consciences, etc.
To wrap things up, I'd still recommend the reading of an article called "Historical Development of new masturbation attitudes in Mormon Culture: Silence, secular conformity, counterrevolution, and emerging reform" for a history of Mormon views on the subject. It seems to me that what started out as something that was 'bad' because it caused health problems (according to erroneous medical opinion of the day), came to be called 'bad' morally because of those cultural perceptions (mainly by Elders McConkie and Kimball) and then 'we' tend to try to say that masturbation must still be 'bad' for you in a physical way, because it is 'bad' the way Elders McConkie and Kimball claimed. Seems like some amazingly bad logic to me.
I'm willing to have a discussion about the morality of masturbation, or of drinking wine, etc., but why are we trying to say that science will eventually show a temporal, physical benefit to all the teachings of the church, or that studies that show the opposite must be wrong. Following a commandment doesn't always lead to better health or longer life. If you want to know more about what I think about it, you should read this post. Either masturbation is healthy, or its not; either it's moral, or it's not; those two have no necessary relation, if you ask me.