I am not sure there is a direct correlation between something like that and age and I don't think it is the least bit useful to assume that it does. Also, even if someone has never set foot into a grocery store, that kind of data is easily found.
I'd rather focus on the policies and the character traits, and less on physical attributes of politicians themselves. Someone could be 100 and still have the morality and empathy required to understand the needs of the average American. Someone could be 20 and a child of privilege having never stepped into a grocery store, and neither know nor care at all about the lives of average Americans.