The 55 year old still has 30 extra years of life. You can't dismiss all of that as useless to the job. That's 30 years of learning about communication, teamwork and productivity through just experiencing life.
I don't know how you make the argument that the candidates are otherwise equal unless one has a resume item reading:
1970-2000: Coma, Mayo Clinic
I don't know how you make the argument that the candidates are otherwise equal unless one has a resume item reading: 1970-2000: Coma, Mayo Clinic