As per the longitudinal data that appeared in the journal named "Progress in Neuro-Psychopharmacology and Biological Psychiatry", subjects with a history of cannabis-consumption are at a lesser risk of developing liver disease particularly NAFLD (non-alcoholic fatty-liver disease) as compared to those who abstain from using it.
A study titled "Cannabis consumption and non-alcoholic fatty liver disease: A three-year longitudinal study in first-episode non-effective psychosis patients" was undertaken by a group of investigators from Spain. In this study, the Spanish researchers tried to assess the association between cannabis consumption and liver steatosis, over a 3-year period. The Spanish investigators were able to note that subjects who continued cannabis consumption for the entire period of study were at a lower risk of developing non-alcoholic fatty liver disease.
Here is what the Spanish investigators were able to conclude from this study:
"Our results suggest that using cannabis could have a protective effect on liver steatosis. The beneficial effect of cannabis at the level of the development of steatosis seems to be secondary to its modulation effect on weight gain and the reduced development of obesity. ... These results are in line with previous studies in the general population, in which cannabis showed significantly lower NAFLD prevalence compared to non-users."