Major in anything the you like and can do well in for "pre-med". If you hate biology, don't major in biology. If you love math, major in math. The courses tested by the Medical College Admissions Test (MCAT) are General Biology with lab, General Chemistry with lab, General Physics with lab and Organic Chemistry with lab. You can major in any subject, take those four courses (and any pre-recs for those courses) do well in them and your major, and get into medical school.
I was extremely hardcore when it came to science. I had no intention of becoming a physician but loved (LOVED) science. Ended up with a double major in biology and chemistry plus double minor in math and physics. Headed off to graduate school (Biochemistry and Molecular Biology) but ended up in medical school after a career as a research scientist (medicine can grow on you especially if your research is purely applicable to medicine).
If I had it to do over again, and I knew for sure that I wanted to enter medical school, I would major in American Studies, minor in Spanish, take the pre-med courses and never look back. In terms of usefulness, my science background is nice but day to day, as a surgeon, American studies would be more interesting and Spanish would be more useful.
The subject matter of your major is not going to impress (or not impress) an admissions committee. Your performance in your major is going to impress (or not impress) an admissions committee. A solid GPA plus a good performance on the MCAT coupled with strong extracurricular experiences, LORs and a well-written personal statement will get you into medical school provided you don't ruin your interview.
There is no particular major that is directly applicable to your coursework in medical school. You need to have an interest in medicine and good study skills. Anything else, including what you ultimately choose for an undergraduate major, is just one of the many hoops that you will be jumping in the medical school admissions process. You might as well major in something that you love, are interested in and can do well in.
