So after reading through the repo linked, if I were trying to do any sort of analysis with that data, I think I would probably not use the data from that column, at least not without significant transformation. As a general rule, you should only impute data where you have a reasonable expectation that your imputation approximates imputed value appropriately. This would seem to be even more true for an epidemiological dataset, where I would expect the information value of age to be high.
I think that if you knew more about how this data was collected, that would probably be most informative in you decision to include or exclude the column.