Proverbs 16:24 Pleasant words are a honeycomb, Sweet to the soul and healing to the bones.
Proverbs 17:22 A joyful heart is good medicine, but a crushed spirit dries up the bones.
How much fun could we have with these verses? There seems to be at least three directions we can go in our interpretation of these "bones" verses in Proverbs:
1. We could simply dismiss them as statements of the obvious ("meatball sandwiches are tasty; good news is nice to have"), and go on to the next verse. I will admit that this was my initial interpretation.
2. We could use these verses to develop a rather technical discussion of the medicinal qualities of righteousness (i.e., always look for spiritual causes of sickness and prescribe spiritual cures of good news and joyfulness, "Three smiles, two Psalms and a Proverb a day and that ulcerative colitis will clear right up"). This is, in fact, how several have interpreted these verses. By hyper-literalizing the text, they create solutions (& problems) that aren't Biblical. Are these verses God's idea of a medical textbook? Hardly. So, this interpretation is out because it's unfaithful to the text. On to interpretation #3.
3. After looking into it some more, I found this sensible and contextually appropriate comment by Bruce Waltke on 16:24:
This verse draws the subunit on competent speech to its climactic conclusion. It compares the extraordinary remedial power of morally and aesthetically pleasing words to overflowing honey….The metaphor is explained in verset B: honey uniquely is both sweet and a remedy. Sweet to the soul connotes their pleasing and attractive style to the audience. And a remedy connotes that their substance is an instrument of healing to those hurt by the damaging speech of fools (see 4:22). The synecdoche to the bones (3:8) refers to the restoration of the entire person or community, both the immaterial and material aspects. Normally medicine is bitter, and what is sweet is not medicinal. Both properties, however, are necessary. Were healing words bitter, the tonic would not be consumed and of no benefit.
More simply, "bones" aren't just bones. Waltke argues that bones is a synecdoche - today's new word! Synecdoche is a figure of speech where a part is used for the whole. E.g., when I say I won't harm a hair on your head, I'm (hopefully) referring to your whole person and not just the thin things protruding from your follicles. Thus, in Proverbs, "bones" is much bigger than just my bones.
Biblically, “bones” often means much more than those long white things in the middle of my arms; it represents the innermost part of the body, thus the person (see Ps. 6:2; 22:14; 31:10; 34:20; and so on). This means that those who take these verses and speak so strongly of the medicinal quality of righteousness and goodness (see #2 above) make the mistake, not of going too far, but not going far enough. The goodness of righteousness extends far beyond our physical health, even to the whole person and the whole community. Do good words do good to our physical, joints-and-tissue-and-bones body? Yes. But the truth is much grander; our words can do good to the whole person, that person made in the image of God. We, with Christlike words, can do something doctors can never hope to accomplish: minister to the whole person, body/soul/mind/strength.
I think the other mistake is that this interpretation gets way more specific than God’s Word lets us. This is an interpretation error is common in some fundamentalist/supra-Scriptural camps, and one that leads to all sorts of problems. One way to guard against this error is have good commentaries and teachers; when we go beyond what the church has taught about these passages and claim to have found the "new and improved - health secrets from Proverbs!!", that breeze we're feeling is because we are out on a tiny limb.