If you want to improve human health, the best way might not be to work on improving human health. It might be to work on something completely unrelated, like physics. Some of the greatest inventions of the medical field had nothing to do with medical researchers. For example, the x-ray was not invented by medical researchers and yet it is one of the most important things in the medical field today. Electricity generation was not created to improve medical health but it lets us run complicated equipments that help us not only in assisting the health industry but also in understandig biology better through things like CT scans. Similarly, the laws of thermodynamics were not discovered by looking for fundamental laws of science but by Sadi Carnot trying to improve the steam engine The revelation that nucleic acids carry genetic information did not come to people looking for the carriers of genetic information but to people working with pneumonia. One of the most used tools by archaeologists, carbon dating, was proposed by a physicist, and not by archaeologists. In fact, archaeologists were the ones who thought it wouldn't work. All of this is because the world in reality is not rigidly divided into subjects. It is we who do the balkanization into medicine, physics and so on. So, in short, when you want to do something, it might be a good idea to also do some things that are not the thing that you want to do.