That's the prediction from computer models that used real clinical data to predict the effects of small reductions in salt intake.
Cutting daily salt intake by a half teaspoon -- about 3 grams -- would not be enough to bring most Americans down to the goal of 3.7 grams a day recommended for about 70% of adults. It wouldn't even get us down to the 5.8 grams a day recommended for lowest-risk adults.
That's because the average U.S. man gets about 10.4 grams a day and the average U.S. woman gets about 7.3 grams a day.
But cutting back by 3 grams, or even just 1 gram, would have huge effects across the population, Bibbins-Domingo and colleagues find.
And here's the best part: To get the benefit, you don't have to do anything. Of course, there is a catch.
Food manufacturers would have to stop putting so much salt into processed foods.
The U.S. Department of Agriculture says that 77% of the salt in the American diet comes from processed food. Only 6% is shaken out at the table, and only 5% is sprinkled during cooking.
Would we miss that salt in processed foods? Not if we're like the British.
"In the United Kingdom, a population-wide reduction in dietary salt of 10% was achieved in four years without a reduction in sales of the food products included in the initial effort and without consumer complaints about taste," Bibbins-Domingo and colleagues report.
There's more good news. Once people cut back on salt -- whether or not they know they are doing it -- they begin to prefer less salt in their food. This happens in a matter of weeks.
The bad news is that food makers probably won't do it on their own. Although some manufacturers already are putting less salt in their prepared foods, others are adding even more.
In an editorial accompanying the Bibbins-Domingo study, Johns Hopkins researchers Lawrence J. Appel, MD, MPH, and Cheryl A.M. Anderson, PhD, MPH, call for federal regulations.
"As we deliberate health-care reform, let us not neglect this inexpensive, yet highly effective public health intervention for the prevention of disease," they say.
Regulations likely would be opposed by industry. New York City already is trying to regulate salt in prepared foods; the effort is opposed by the Salt Institute, a trade association representing the salt industry.
"Salt reduction doesn't provide any positive health benefits and may diminish benefits when it relates to diet," said Morton Satin, the Salt Institute director of technical and regulatory affairs, in a news release.
The editorial and the Bibbins-Domingo study were published in the Jan. 20 online issue of the New England Journal of Medicine.