Nursing degree program requires that students take the course Nursing Research and actually perform some research , so hey there you go.
The big advantage is that one does get the needed clinical experience, knowledge, patient relation skills, clinical assessment, etc and a very very realistic picture of what one is getting into.
2nd if one participates in their field like in the hospital they work in and contribute research wise and stuff that's a big plus.
The list is long but I just wanted to correct the ones who had the opinion that nurses do not qualify or get into med school. I think that most nurses want to be nurses that 's why they do not go for medicine but still there are those and many of them BTW who have taken this route to become superb physicians with a wholistic view of patients.