Although I totally respect the power of food, and the importance of getting your nutrition essentials and diet therapy, I think that some people do tend to overdo it.
I mean, diet and nutrition therapy is great, but I think that its easy to take that too far as a therapy alternative when chemical medication really is the better option.
For instance, you see these people trading in cancer medication and therapy for a diet and nutrition therapy, thinking that they can cure cancer just by what they eat.
Although this may be true in very specific, very limited circumstances, in general, you really need to follow a doctor's regimen with such a serious condition.
So I think that its better to combine the two -- eating a proper diet can absolutely do wonders for your health, but it can't substitute medication in some circumstances.