The sodium supplied by dietary salt plays a very important role in controlling your blood pressure levels and maintaining the balance of fluids in your body. Most people can handle a very wide variation in dietary salt -- from very low levels to very high levels -- without significant problems. Some individuals, however, will have an elevation in blood pressure, as well as more "stiffness" in their blood vessels, when they ingest more dietary salt than they need. These people are called "salt sensitive."
A relatively large proportion of people with high blood pressure seem to have salt sensitivity. Whether you have salt sensitivity or not appears to depend on several factors, including genetics, race (black individuals are more likely to be salt sensitive), body mass (overweight people have a higher incidence of salt sensitivity), and exercise levels (exercise can reduce salt sensitivity).
Why Salt Restrictive Diets Help
While no readily available tests can determine who is and who is not salt sensitive, current recommendations are for virtually everyone with hypertension to be placed on a salt-restrictive diet. This recommendation is made for three reasons. First, if you have hypertension, the chances that you are salt sensitive are relatively high. Second, even if you are not particularly salt sensitive, there is likely to be at least some reduction in your blood pressure with a reduced-salt diet. And third, restricting the salt in your diet can make most anti-hypertensive medications more effective.
Recommendations On Salt RestrictionAll the major expert panels who have weighed in on the matter recommend salt-restrictive diets for people with hypertension.
Food labels don't actually list salt content, but instead list sodium content. Accordingly, most of the published guidelines for treating hypertension recommend reducing dietary sodium from the 150 to 200 meq/day that most people get with a typical American diet down to 100 meq/day, or even less. (Forty-four meq of sodium equals one gram.)
Furthermore, since a lot of the salt we get each day comes from processed foods, public health experts (and others) are lobbying hard for government regulations that will restrict the amount of sodium used in food processing. Their aim is to substantially reduce salt intake across the population. While their hearts are in the right place, and while they can make a reasonable argument for wanting to accomplish this goal, quite a bit of controversy swirls around a widespread, federally-regulated policy of salt restriction.
Practical Tips for Reducing Salt Intake
- Sell your salt shaker; never add salt at the table.
- Check the labels of condiments and convenience foods, many of which are absolutely loaded with salt.
- In fact, check the labels of any processed foods you may eat -- such as sauces, canned vegetables, and cereals -- and look for low-sodium brands.
- Eat lots of fresh fruit and vegetables; among other benefits, the potassium contained in these food items helps to balance the effect of salt.
- Try not to cook with salt; if you must add salt, add it at the end of the cooking process (you'll use less).
Adrogue, HJ, Madias, NE. Sodium and potassium in the pathogenesis of hypertension. N Engl J Med 2007; 356:1966.
Weinberger, MH. Salt sensitivity of blood pressure in humans. Hypertension 1996; 27:481.