Move oven rack to lower position so that the top of the pan reaches the middle of the oven Preheat oven to 350 C .Grease bottoms of two loaf pans. Mix sugar and butter in a large bowl. Stir in eggs until well blended Add bananas, buttermilk and vanilla and beat until smooth Stir in flour, salt and baking soda until just moistened.
Stir in nuts and blueberries. Pour into pans and bake for approximately 1 hr or until toothpick inserted in center comes out clean.
Cool on wire rack and slice after it cools completely.
Tastes great when heated slightly in the microwave and spread with butter