Go to MIT. They have a stronger departments in biology, chemistry, physics, and engineering. They will also have amazing opportunities for research as an undergrad, which will take you miles ahead in med school admissions. MIT is better than CMU and also has better financial aid... they will take care of you intellectually and financially for 4 years.
Going to MIT will also mean that you will be able to clinical volunteering and/or research at the nearby hospials at Harvard (if you are lucky enough), BU, and others.