The DASH Diet, AKA the Dietary Approaches to Stop Hypertension, is specifically designed to lower blood pressure. There is encouraging clinical evidence that following the guidelines of this diet will lower blood pressure.

Diet Features

• Lowering consumption of sodium, saturated fats, and cholesterol
• Eating nuts, fish, and whole grain foods
• Reducing sodas and other sugary beverages
• Rich in magnesium, potassium, and fiber

Sources and further reading: 

• NIH DASH Resource Center - Includes guidelines, menu samples & recipes</li>
• DASH Clinical Study Info - Somewhat critical summary of the information "proving" that DASH lowers cholesterol.
• Cardiovascular Health Guide - From the National Heart, Blood, and Lung Institute. Includes information on sleep disorders.