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By Ray Hainer

THURSDAY, October 20, 2011 (Health.com) — Eighty-eight percent of U.S. children and adults consume more sodium per day than the amount recommended by federal dietary guidelines, according to a new report released today by the Centers for Disease Control and Prevention (CDC).

And most Americans aren't just exceeding these guidelines; they're shattering them. The U.S. Department of Health and Human Services and the U.S. Department of Agriculture recommend that adults and teens limit their daily sodium intake to 2,300 milligrams, but according to the report the average intake is 3,513 milligrams—53% above the suggested limit.

The picture is even worse among the subpopulations for whom the daily recommended limit is 1,500 milligrams: people over 50; blacks; and those with high blood pressure, diabetes, or kidney disease. Members of these groups, which account for nearly half of the U.S. population, tend to be especially sensitive to sodium, yet 99% of them exceed the recommended intake and the average person more than doubles the 1,500-milligram limit.

"We're consuming far more [sodium] than is recommended, no matter what group you're in," says Janelle Peralez Gunn, a coauthor of the report and a public health analyst with the CDC's Division for Heart Disease and Stroke Prevention.

The researchers weren't surprised by the data, but the findings underscore that health officials "have work to do" in educating the public about the dangers of excess sodium, Gunn says. Consuming too much sodium can lead to high blood pressure (hypertension), which can in turn contribute to life-threatening health problems such as heart attacks and strokes.

For most people, locking away the saltshaker won't be enough to lower their sodium intake to healthy levels, since three-quarters of the sodium consumed in the United States comes from packaged foods and restaurant meals. "A lot of people tend to think…'I don't add salt to my food,' without realizing that they've probably already exceeded—and in some cases probably doubled—their [recommended] intake before they've even picked up the saltshaker," Gunn says.

Reducing sodium intake on a population-wide level will almost certainly require partnerships between government and the food industry to reduce the use of sodium during food processing, Gunn and her colleagues suggest. A public-private partnership of this sort has led to an estimated 10% reduction in salt intake in the UK, the report notes, and New York City is spearheading a similar partnership in the U.S. inspired by that effort.

More than two dozen food manufacturers and restaurant chains—including Kraft, Heinz, Goya, and Subway—have already signed on to the program, known as the National Salt Reduction Initiative. These companies have pledged to reduce the sodium in their foods by up to 25% by 2014.

The new report is based on a nationally representative survey conducted by the CDC between 2005 and 2008, which included a detailed diet questionnaire. Public awareness of excess sodium has likely risen since 2008, thanks to increased media coverage and public-health campaigns such as the New York City initiative, but the results would not be much different if the survey were conducted today, Gunn says.

"Given that the intake is fairly high, even if we've had some impact in more recent years the vast majority of people are still going to be consuming more sodium than is recommended," she says.