Why is massage therapy such good medicine? Because it helps move lymph, blood and oxygen to the various organs and tissues in ways that normally don't happen in the bodies of most people. This is especially true for those who don't exercise: for them, massage therapy is critical for maintaining any degree of health.
There's also the "touch factor" of massage therapy that I believe to be remarkably healing. There's something almost magical about the human touch, and its qualities can't be measured with scientific instruments (yet), but researchers know very well that it has powerful physiological effects: touch calms people. It reduces blood pressure, it boost immune system function, and it makes people feel loved. These are very important for those seeking health and healing. (And if you don't believe me, just volunteer at a nursing home some time and offer free hand massages to the patients. I've done this, and you'd be amazed to see the different it makes in the people you're touching.)
The human touch is powerful medicine, which is why I find it so bizarre that doctors seem so afraid of touching their patients. But you don't need a doctor for this kind of healing: find yourself a good massage therapist and get some healing on a monthly basis.