Does a person's diet really influence the treatment process of certain medications? I would say so. The issue is that researchers have barely scratched the surface on the theory, most likely because it's difficult to actually see the interaction. I believe that if all doctors/practitioners inquired deeper about their patients' dietary habits, medical science would once again become personal.
I have this fear that a visit to the doctor's office is changing more and more into a visit to the post office, where the focus is about getting people in and getting people out. This may be just a skewed observation of mine but all human beings wish to maximize the efficiency of their time so maybe not?