Washington ? Best known for deciding whether medications are safe and effective, the Food and Drug Administration is weighing whether to crack down on plain old salt, which doctors say is harmful in the quantities most Americans consume.

At a hearing today, the agency will begin collecting expert testimony on the role excess salt in the diet contributes to high blood pressure, heart disease and strokes. An increasingly vocal medical community has joined consumer groups to demand government intervention, and the review could lead to federal limits on the salt content of processed foods such as canned soups and breakfast cereals.

In a carefully calibrated response, the food industry has acknowledged the problem but called for voluntary solutions rather than government regulation. More than 75 percent of the salt the average American consumes comes from processed foods and restaurant meals.

At issue is whether the FDA should change its official classification of salt as “GRAS” – Generally Recognized as Safe – and instead declare it a food additive subject to limitations.

FDA officials say they view excess salt in the diet as a serious public health issue, but the agency is keeping its options open.

“We certainly recognize that it’s a big problem for a lot of people, and consumers should have choices if they want to reduce their salt intake,” said Laura Tarantino, director of the FDA’s office of food additive safety, who is taking a leading role in the agency’s review.

The agency’s involvement is long overdue, some activists say.

“For the first time in 25 years, the FDA is showing an interest in lowering sodium levels in the food supply,” said Michael Jacobson, executive director of the Center for Science in the Public Interest, a consumer group that petitioned the agency to take action.

Jacobson’s group had been waging a campaign to get the FDA’s attention, but prospects for action improved markedly after the AMA made it a top priority last year. “We came to the conclusion that the evidence is overwhelming,” Havas said.

Too much sodium has been linked in scientific studies to high blood pressure, a major risk factor for heart disease and stroke.

The National Academy of Sciences recommends that adults consume no more than 2,300 milligrams of sodium daily, roughly the amount contained in a teaspoon of salt. The target is lower – 1,500 milligrams – for people at higher risk for high blood pressure, including those older than 50 and blacks.

But Americans typically consume about 4,000 milligrams of sodium daily.

The AMA cites estimates that 150,000 lives could be saved annually if the nation were to reduce its sodium consumption by 50 percent, a goal the doctors’ group says can be attained within a decade.

It probably can’t happen without the cooperation of the food industry, and producers are skeptical.

“Claims about (low) salt are often a turnoff for consumers,” said Robert Earl, director of nutrition policy for the Food Products Association, a trade organization. “Consumers automatically think it means the food isn’t going to taste good.”