Entity Framework table for each type - select only base type columns

First we use EF 4.3 Code and have an object model:

class Content {  }

class Product:Content { }

class News:Content { }

They are displayed as a table for each type.

There are scenarios where I just want to load only the columns belonging to the base table, for example, a list of all the content headers. But the request is like

from c in Content
where c.IsDeleted == false
select c

leads to some really nasty SQL with joining two other tables. Is there a way to make EF just make a selection from the base table only without joining other tables?