Preheat oven to 350 degrees F. Grease the bottom and 1/2 inch up the sides of a 9x5x3-inch loaf pan; set aside.
In a large bowl stir together the flours, brown sugar, the 1/2 cup sunflower kernels, the flaxseed meal, the 2 tablespoons sesame seeds, the 2 tablespoons poppy seeds, the baking powder, baking soda, and salt. Make a well in the center of the flour mixture; set aside. In a medium bowl beat egg with a fork; stir in buttermilk and oil. Add egg mixture all at once to flour mixture. Stir just until moistened (batter should be lumpy). Spread batter into prepared pan. Sprinkle with the 4 teaspoons seeds.
Bake for 45 to 55 minutes or until a wooden toothpick inserted near the center comes out clean. Cool in pan on a wire rack for 10 minutes. Remove from pan. Cool completely on wire rack. Wrap and store bread overnight before slicing.