It's clearly worth a try if you have blood pressure above the optimal limit for normal, 120/80 millimeters of mercury (mm Hg), or risk factors for hypertension. For other people, moderate sodium restriction is a more realistic goal. Evidence for the revised recommendations comes from a government-funded trial known as the Dietary Approaches to Stop Hypertension (DASH) study, which found that cutting sodium to 1,500 mg lowers nearly everyone's blood pressure. Although the effect was slight in those with normal blood pressure, the low-sodium diet reduces systolic blood pressure (the upper number) by 3 to 7 mm Hg in those with high blood pressure or risk factors for it. Those factor include being older or black, having a family: history of high blood pressure, or having high-normal blood pressure.
The benefits of sodium restriction were especially striking when combined with the DASH diet-a diet high in fruits, vegetables, whole grains, and low-fat dairy products.
Those who consumed the least sodium along with the DASH diet dropped their systolic pressure by an average of 11.5 mmHg.
For people with normal blood pressure and no risk factors, the more modest goal of 2,300 mg, achievable by adopting the DASH diet alone, would presumably help fight the upward creep in pressure that tends to occur with age.
Because some people respond dramatically to sodium, even those with high blood pressure don't necessary have to make it all the way down to 1,500 mg to see a meaningful decline, although the less sodium consumed, the lower blood pressure will likely go. Conversely, not everyone responds to a low-sodium diet. So if you give it several months of serious effort and see no improvement you can ease up on severe restrictions.