Detach all entities in a DbContext before loading it again with data. The only issue I have with this is, that the detached entities are still in memory.

DbContext.cs

...
public void DetatchAllEntities()
{
    ChangeTracker.Entries().Where(dbEntityEntry => dbEntityEntry.Entity != null).ToList().ForEach(e => e.State = System.Data.Entity.EntityState.Detached);
}
...