Abstract: An optical fiber which is enclosed within a polymeric jacket. At least a portion of the jacket material comprises a particulate material which is at least partially soluble in water, such that a solution can be formed which has reduced reactivity toward the optical fiber, relative to pure water. An amount of such material is incorporated in the jacket, sufficient to delay the expected onset of accelerated fiber fatigue in a standard fatigue test by at least a factor of 2 relative to an otherwise similar fiber enclosed within a jacket which is free of the particulate material.