From BOL: "Not supported. Future compatibility is not guaranteed."

http://msdn.microsoft.com/en-us/library/ms187348.aspx

Why don't you just create and/or refresh statistics to get realistic data ?

You could update system tables using dedicated admin connection (put "admin:" in front of server name) and starting the sql instance in single-user mode ("-m;" startup parameter), but why doing such invasive stuff when you can probably go with normal, supported methods?