For decades, doctors and dietitians have been urging people with high blood pressure to throw out the salt shaker to reduce their risk of heart disease and stroke. Now we're finding just how crucial this advice can be.
Research supported by the National Heart, Lung and Blood Institute had shown that dietary changes could substantially lower blood pressure in people with normal and high pressure. Called the Dietary Approach to Stop Hypertension, its eating plan emphasized fruits, vegetables and low-fat dairy products; included whole grains, poultry, fish and nuts; and went easy on sweets, sugary beverages and fat.
Now the New England Journal of Medicine reports that the diet, when combined with reduced sodium intake, can lower the average systolic blood pressure (the top number in the blood pressure reading) by 11.5 millimeters of mercury in just 30 days for people with hypertension.
A typical U.S. diet include 3,330 milligrams a day of sodium, equivalent to almost 1 1/2 teaspoons of salt; the reduced-sodium diet included only 1,500 milligrams a day, just over half a teaspoon.
To give this research perspective, clinical trials suggest that reductions in sodium intake can reduce a person's risk of a life-threatening stroke by 38% and the risk of coronary heart disease by 16%.
Such statistics can sound dull, but when you, a friend or relative are among them, they suddenly become terribly real. This dietary advice is a potential lifesaver for each of the 50 million Americans with high blood pressure--a third of whom are unaware of their condition.
Certainly those who know they suffer from hypertension would be well-advised to begin following the basic dietary plan as well as taking steps to reduce salt and foods rich in sodium.
But some scientists continue to resist the idea of sodium-reducing dietary advice for the general population.
Research does not appear to support their concerns. Also, according to the government's most recent dietary guidelines, which outline appropriate nutritional intake for Americans, reducing sodium intake could benefit bone health as well as blood pressure. High intake may encourage loss of the mineral calcium and increase the risk of developing osteoporosis.
If by now you are considering condemning that salt shaker to the bin, bear in mind that three-quarters of sodium consumed is via processed foods--added to everything from obviously salty snacks to everyday staples like bread and cereals. But just as producers responded to demands for low-fat foods, they are slowly rising to the challenge of reformulating with less sodium. This makes it crucial to master the label lingo.
Look for "sodium-free" foods, which have 5 milligrams or less of sodium per serving; "very-low sodium" products, which have 35 milligrams or less; and "low-sodium" products, which have 140 milligrams or less. Beware, however, of "reduced-sodium" foods. Although they must contain at least a quarter less sodium than the original, they can still be rich in total sodium.
If at first your taste buds complain over such sodium-slashing action, rest assured they quickly adapt. With that a preference for less salty foods becomes a natural choice and you could see blood pressure starting to fall. More information about the DASH diet and tips for cutting sodium can be found at the American Dietetic Assn. Web site (http://www.eatright.org).
Amanda Ursell, a dietitian, is a London-based freelance journalist who writes about food and nutrition. Her column appears twice a month.