One should perhaps conduct life extension research if possible. There are areas of the biological sciences that investigate why humans grow old and die. Perhaps through science, biology, and technology, aging could be stopped and/or reversed. If one is taking pre med requirements, perhaps one should eventually go into an area of science that deals with life extension and/or abolishing aging. Humans grow old and die right now, it seems. This may not have to happen. Humans could perhaps live indefinitely through either nanotechnology or biomedical means.
If humans lived indefinitely, this would perhaps have many implications for society. It may ultimately be best for everyone on Earth. Perhaps, eventually, humans might be able to colonize other planets. Health is a good thing. There are many ways to participate in the health professions. If one is taking pre med requirements already, it seems it would not be particularly difficult to transition into biomedical gerontology or some other area of study that could further life extension research.
Aubrey de Grey is a biomedical gerontologist who promotes research into life extension. He wrote a book called Ending Aging. He promotes something called Strategies For Engineered Negligible Senescence. He runs the SENS Foundation. Aging should be stopped or abolished. At least, humans should be able to exercise control over it, if they wish. There are probably other scientists attempting to eliminate aging as well. This is an area of research that perhaps can be both interesting and have much room to grow and expand.
Diseases kill humans, so they are bad, and should be cured. Therefore, since aging kills humans, it is also bad, and should be stopped and preferably reversed. This may take time, money and research to accomplish. One could probably build a whole career around life extension it seems. So if one is taking pre-med requirements, then one should perhaps consider venturing into life extension research.