Id say that this is only good if it helps GPA and MCAT scores. You might get an occasional adcom that cares about the classes you took, I haven't heard too many stories of that...especially in DO schools.
So, in short, most likely schools could care less what you major in, much less any emphases you have.
Importance is GPA, MCAT and how well you did in pre reqs and upper level science(esp. bio) courses
Just my opinion on it
(thats not to say not to do it if you enjoy it though!)