A fiber optic cable can comprise spheres or balls that are coated with a water absorbent material, such as a super absorbent polymer ("SAP"). The spheres can provide clean and efficient carriers for introducing SAP into the cable during manufacturing. The spheres can have a diameter in a range of 20 microns to 2.5 millimeters and can be disposed in the cable's interstitial spaces, for example between the cable's optical fibers and a surrounding buffer tube. The SAP material can adhere to the spheres as a cross-linked coating or via electrostatic charge, for example. Beyond absorbing any water that may enter the cable, the spheres can provide cushioning or mechanical protection for the optical fibers. When the cable receives stress, motion among the spheres can absorb the stress to shield the fibers from damage.