In my experience (perhaps limited since I only have an undergrad degree), I suspect that people change disciplines, both in academia and careers, much more than you're estimating, even between completely unrelated fields. (Exercise which I don't have time to do right now: Look up lists of faculty at various universities/research companies, and note their credentials.) Also, note that having a PhD more or less completely overshadows whatever you did in undergrad.
How much overlap is there between required courses for biochem and medicine? It's plausible that you could do a double major, depending on that.
One cannot 'major' in two disciplines in the country where I'm going to study.
I graduated from high school and wish to further my education formally by studying for a bachelor's degree in order to become a medical researcher. I could, for instance, take two different academic paths:
Study Medicine at undergraduate level and then do a postdoctoral fellowship.
Study Biochemistry at undergraduate level, then study for a PhD at graduate level, and finally do a postdoctoral fellowship.
Since I will do these studies in Europe, they each take approximately the same amount of time, namely 6 to 8 years.
Do I want to do treat patients? No, I do not. But I am considering Medicine because it can be a buffer against my own mediocrity: in case I turn out to be a below average scientist, I will be screwed royally. From my personal job shadowing experience, Medicine, on the other hand, requires mere basic intellectual traits, primarily the ability to memorize heaps of information. And those I think I have. To do world-class research though I'd have to be an intellectual heavyweight, and of that I'm not so sure.
How do I decide what path to follow?
The reason I'm asking you strangers for advice is because I evidently have biases, such as the pessimism/optimism bias or the Dunning–Kruger effect, that impair my ability to reason clearly; and people who know me personally are likewise prone to make errors in advising me because of biases like, say, the Halo effect. (Come to think of it, thinking that I can't become an above average scientist is in itself a self-defeating prophecy!)
Do you think that one ought to always seek advice from total strangers in order to be safeguarded from his/her own biases?
PS: I apologize if I should have written this in a specific thread. I'll delete my article if that's necessary.