One way to cut down on sodium consumption may be to keep the salt shaker on the table, a new study suggests.

Naturally, there's a catch. The food on the table has to be low-sodium to start with.

But the study, involving 11 students at the University of Pennsylvania, found that when the sodium content of their food was cut by about 50 percent, they compensated by adding a lot less than that from the salt shaker.

For many Americans, the sodium in salt contributes to high blood pressure. The study suggests that one way to lower sodium consumption yet retain a palatable diet is to "consume food with lowered salt while using a salt shaker."

The research, done at the University of Pennsylvania and the Monell Chemical Senses Center in Philadelphia, was reported in the Journal of the American Medical Association.

The study lasted 13 weeks. In the first three weeks and the last week, the students ate a normal hospital diet unrestricted in sodium. During the other 10 weeks, sodium was reduced by half.

The students had unlimited access to a salt shaker and were told to use as much salt as they wanted but were not told that their use of table salt would be measured.

Only one of the 11 students approached completely compensating for the 50 percent sodium cutback by adding table salt. On average, they added only enough table salt to offset 20 percent of the sodium cutback.

Of the dietary sodium consumed by most Americans, about one third occurs naturally in food, one third is added by manufacturers during food processing and one third is added by the consumer during cooking or at the table.

Previous studies have shown that people's taste preference often changes when they go on a low-sodium diet; they come to prefer unsalted food to salty food. But the Pennsylvania study found "no significant changes in taste perception" among the students.

One explanation, researchers said, is that because table salt puts salt on rather than in food, the person eating it retains "enough sensory experience with salty tastes to prevent preference changes."