Frankly, I was shocked to see that AADSAS asked me for my ethnicity on my application.
Ethnic quotas are totally unheard of at my university's (not in US) dent/med/pharm/law programs. There is no preference for undergrad major either. So fashion design works just as well as engineering, math, biology, as long as it's from a 4-year institution in North America. In particular, the likelihood of a med school applicant being accepted depends solely on how well he/she fits into my university's med school's selection methodology, as follows:
The applicant's GPA predominates. Interview performance is a distant second, and extracirrculars come a close third. It's extremely hard to be rejected if you have a 4.0. You pretty much have to recite a passage from Mein Kampf during the interview or have done absolutely no extracirrculars since you were 16 years old to be rejected with this GPA. MCAT works on a quasi-cutoff basis; if you have >= 9 on every section, then you're MCAT will NEITHER hinder NOR HELP your application one bit. If any section is <9, you can still compensate with a strong (>3.97) GPA, though a <=7 will LIKELY kill your chances regardless.
AT LEAST half of the med students at my school are Asian. Deduce what you will.