Sodium won't kill you? Scientists shake up what we know about salt

The more salt you consume, the higher your blood pressure rises. One in three American adults has high blood pressure, a major risk factor for stroke, kidney failure, and heart attack. "Steer clear of packaged junk food, read the labels for sodium content, and stick to the outer portions of the supermarket, which is where the fruits, vegetables, and (unsalted) nuts are," Dr. Ostfeld says. Most of us should keep sodium intake below 2,300 milligrams a day. If you have high blood pressure or are over 50, cut back to 1,500 milligrams.More from 10 best foods for your heart
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(CBS) It's been common wisdom for years. Too much sodium leads to high blood pressure which leads to heart disease and possibly death. But a new study out of Belgium might just shake up what we think we know about salt.

Scientists who studied several thousand subjects for eight years found that not only was low sodium intake not associated with improved health, the group that appeared to consume the least sodium had a 56 percent greater chance of death from heart attack or stroke than the group that was reaching for the salt shaker with every meal.

The study had some major caveats. Researchers only tested sodium levels in participants' urine two times - once at the beginning of the study and once at the end. Sodium levels can fluctuate greatly from day to day, so they may not have captured enough data to get a clear picture. Also, the group studied was white, relatively young, slimmer than the typical American and had normal blood pressure before the study started. Previous research has shown that all those groups tend to be more sensitive to the potentially negative impact of salt.

Still, the findings are a confusing new data point in the public health battle over salt consumption.

New federal guidelines recommend healthy adults consume no more than 2,300 milligrams per day. Some groups are pushing to lower it to 1,500 milligrams a day - the amount currently recommended from African Americans and people who already have hypertension.

Last year, a group of major food manufacturers wilting under public pressure on salt, agreed to cut sodium levels in many of their most popular products. And the New England Journal of Medicine published an alarming study which predicted as many as 99,000 heart attacks could be prevented each year if people cut their sodium intake down to 1,2000 milligrams a day.

So where does the new science lead us on sodium intake? We'll have to see how it shakes out.

The study was published in the Journal of the American Medical Association.