Prov 17:22 A merry heart does good, like medicine, but a broken spirit dries the bones. (NKJ)
Rom 14:17 For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost. (KJV)
As we abide in our Lord Jesus Christ, we have peace and joy.
That joy even has a healthy, healing effect on our bones!