Evidence suggests that a diet that emphasizes healthy eating habits significantly lowers blood pressure in people who have hypertension and even normal blood pressure. This diet is often known as the DASH (Dietary Approaches to Stop Hypertension) diet and is outlined as follows:

• Emphasis on fruits, vegetables, and low-fat dairy foods.
• Includes whole grains, poultry, fish, and nuts.
• It contains small amounts of red meats, sweets, and sugar-containing beverages.

This study aimed further to define the effect of salt on blood pressure and to investigate the effect of a combined low salt / DASH diet. Four hundred and twelve subjects were randomly assigned to eat a controlled diet, which was typical of a normal US diet, or the DASH diet. Within each dietary group, subjects ate foods with a high, intermediate and low level of salt for 30 days.

Reducing sodium intake from the high to the intermediate level reduced the mean systolic blood pressure among those on the control diet by 2.1 mm Hg and 1.3 mm Hg for those on the DASH diet. When salt was reduced to the lowest level, there was an additional reduction in systolic pressure among those receiving the control diet and for those on the DASH diet. The greatest reduction in systolic blood pressure occurred in subjects consuming the low-salt DASH diet, representing a 7.5 mm Hg decrease in non-hypertensive patients and an 11.5 mm Hg decrease in those with hypertension.

Conclusion: the reduction of sodium intake to levels below the current recommendation of 100 mmol/d and the DASH diet both lower blood pressure substantially, with greater effects in combination. Long-term health benefits will depend on the ability of people to make long-lasting dietary changes and the increased availability of lower-sodium foods.v

Note: The duration of this study was very brief – only 30 days. Yet there were still significant decreases in systolic blood pressure. Even greater potential improvement in blood pressure may be possible if patients adhere to a diet that is low in sodium and combines principles of the DASH diet.