You can slow down the progression of the disease and stopping smoking is the most effective way to do this
98 th Congress Technical Study Group Cigarette Safety Act of 1984 (1987) Toward a less fire-prone cigarette, final report to the congress of the technical study group on cigarette and little cigar fire safety, p 41 Gann RG, Harris RH, Kransy JF, Levine RS, Mitler HE, Ohlemiller TJ (1988) The effect of cigarette characteristics on the ignition of soft furnishings, NBS technical note 1241
However, it will not reverse all the existing damage, like severe staining or bone loss
In an analysis of 54 commercially available e-liquids , PG and glycerol were detected in almost all samples at concentrations ranging from 0.4% to 98% (average 57%) and from 0.3% to 95% (average 37%), respectively [35]