You can select any major you want if you're willing to take electives to meet medical school prerequisites. School requirements vary somewhat, but there's generally a strong emphasis on math and science. The Association of American Medical Colleges recommends one year each of biology, English and physics, and two years of chemistry, including organic chemistry.
Natural science majors in biology, physics, chemistry and similar fields are natural fits for medical school and can help you meet most medical school prerequisites. Data compiled by the American Institute of Physics, AIP, from the Association of American Medical Colleges, indicates that, as a group, physics majors applying to medical school in 2012 did better than most other majors applying in the same year on the MCAT. Students with science majors in biomedical engineering, electrical engineering, and neuroscience also excelled on the test.
A math major can make the dizzying array of numbers you encounter as a doctor make better sense. If you plan to do clinical research rather than practice as a physician, or if you plan to do both, a degree in statistics may be particularly helpful. If you opt for a math degree, make sure you take natural science courses to fulfill your premedical requirements. Math majors were also among the best performers on the MCAT in the 2012 list provided by AIP.
Premed majors scored toward the lower end of the MCAT, in the data AIP compiled, compared to students majoring in math and natural sciences. However, a major in a health-oriented field can help you determine whether life as a doctor can hold your interest. Majors such as nutrition, nursing, physical therapy, and sports and exercise science can give you real-world skills as well as ample preparation for medical school.