it helps if your parents are doctors or involved in medicine. my dad is a physician and my mom was a nurse. in my interview, the first thing the adcom member asked me was "so your dad's a doctor in ____ city, is he part of ____ group? I did my residency down there." I said "no, he isn't in that group. he's in _____." the adcom member replied "that's good because that group I mentioned is known for doing unnecessary procedures just to make more money." I of course knew this already and said "yep, my dad isn't very fond of them at all. most doctors in ____ city share that opinion."
he then asked me what specialty my mom did in nursing. I never even thought about that since my mom stopped practicing when I was born. I just told him "I actually don't know. she stopped practicing when I was born and later went back to work voluteering fulltime as a preschool teacher." so, the adcom member, who was an internist, was even interested in knowing my mom was a nurse, not a physician. unfortunately, I wasn't able to use his interest to my advantage since I couldn't answer the question haha. I thought I bit myself in the tongue real bad by not being able to answer it, but after telling the honest truth why I didn't know I think I made up for it. he gave me a very good reaction when I said she went back to work volunteering fulltime as a preschool teacher.
also in the interview, I mentioned how growing up I knew the lifestyle of a physician, the latenight calls that the hospital always made to the house phone waking everyone up, and so on; however, I did not know if that's what I wanted until I got into college and starting shadowing the many areas of medicine when I realized there was a much bigger scope of medicine than my dad's specialty. I said it was actually the ER that convinced me I wanted to be a physician since it was then I saw the full process of diagnosis and treatment for the first time. I had never seen the entire process of a patient coming in on Day1 and leaving on Day X after treatment under my dad.
I only mentioned my parent's backgrounds in 2 sentences of my personal statement.
also, another adcom member, who did not interview me but was present on the interview day, happened to think very highly of my dad as a physician. everytime I saw him he would say, "I know I've told you this, but your dad is very high in my books. Just knowing you're his son leaves a good impression of you on me." he came up to me a few hours before my interview and told me who my interviewer was going to be and what his background was. it definitely helped. he is one of the ppl on the adcom who will vote and give you a score. the adcom meets together and all score each applicant. they add up all your points and the ones with the best totals are granted admission. so, I have 2 adcom members who will be my advocates to the rest of the committee: the one who interviewed me and the other who I know only because of my dad. most applicants will only have the one advocate who interviews them.
so, as you can see, my dad being a physician only helped me. it will especially help you in your interviews, I think. in your PS, mention it but I wouldn't focus on it. the thing is one of the questions the interviewer will always ask you is what other careers have you thought about other than being a physician. you need a good answer to that and that answer should be something that your parents being doctors had no influence on. I was heavily into debate in HS so I talked about and realized how after 4 years of it that a career in law/politics wasn't for me. anyways, just keep these things in mind. your PS should show you reached the conclusion you want to be a physician. it should not start off saying "i wanted to be a doctor my whole life, so I volunteered at the hospital, did research, etc. etc. to get into med school." it should say "one of my interests was health care so I started to get some hospital exposure, shadowing, etc. and all of my experiences in the end convinced me I wanted to be a doctor." it would help if you actually DID try different possible career interests haha. you don't need to mention those other career intersts in your PS, though. just be prepared to bring them up during interviews when they are really trying to figure out if you truly want to be a physician or not and that you have put lots of thought into it.