Try this:
=DateDiff("m",[DOB],[CurrentDate])\12 & " year(s), " & DateDiff("m",[DOB],[CurrentDate]) Mod 12 & " month(s), " & DateDiff("d",[DOB],[CurrentDate]) Mod 12 & " day(s)"
Or
the following will show - if the person is still Living - "Age: " in front of years(s), Month(s) and day(s)
if...