STEVE INSKEEP, HOST:
We'll talk next about a dangerously tasty substance. Many of us add salt to almost everything we cook or bake. Most public health experts say we consume way too much, and they want us to cut back to lower our risk of heart attacks or strokes. We have two reports today on salt, starting with the question of why we like it so much to begin with. Here's NPR's Dan Charles.
DAN CHARLES, BYLINE: When you start investigating salt, you run into a paradox and a mystery.
PAUL BRESLIN: Salt is a really interesting chemical to us.
CHARLES: That's Paul Breslin, a researcher at the Monell Center, a whole research institute in downtown Philadelphia devoted to the senses of taste and smell. Breslin says the paradox is, on the one hand, we absolutely need these crystals of sodium chloride to survive.
BRESLIN: If you don't keep up your sodium level in your body, you will die.
CHARLES: Yet, if you eat too much salt, that's bad, too. And most of us eat at least 10 times more than our bodies actually require.
BRESLIN: There's no question that people who have high salt intakes are at risk for a stroke and heart attack and death from these, and that lowering their intake will save lives. In Finland, when they lowered the salt intake, the stroke and heart attack rates went way down, and mortality went way down as a consequence of that.
CHARLES: The average person in Finland had been eating a lot more salt than Americans do. The anti-salt campaign brought that level down to around the global average. Now there are skeptics who say, for most people, that average level is perfectly healthy. But the World Health Organization and here in the U.S., the Centers for Disease Control and Prevention both say people should cut salt consumption even more, by about a third.
This won't be easy, because people like salt. And this is where we get to salt's mystery. Scientists aren't exactly sure how much of our taste for salt is nature, and how much is nurture. Paul Breslin says a massive international study conducted in the 1980s suggests maybe we're born with it.
BRESLIN: All across the planet, with a few cultural exceptions, most people consume - within a given range of variability - more or less the same amount of sodium.
CHARLES: The exceptions are people who can't easily get salt, like isolated tribes in Amazonia. Everywhere else - from small villages in China to Chicago - people consume similar amounts, much more than our bodies need.
BRESLIN: And that includes people who have no access to commercial food, even, no access to processed food.
CHARLES: If humanity's taste for salt preference really is so universal, Breslin says, it's going to be really hard for any government to convince people to use less of it. On the other hand, there's also some evidence that our preferences do shift, based on what's around us. Gary Beauchamp - who's director of the Monell Center - says the first evidence for this came from the stories of doctors who ordered patients with high blood pressure to switch to a low-sodium diet.
GARY BEAUCHAMP: What the people reported was that it was awful at first, but then after a while, it wasn't quite so bad.
CHARLES: It was a little bit the way our eyes adapt to a dark room.
BEAUCHAMP: After they did that for a while, when they went back to their normal food, it was too salty.
CHARLES: At the Monell Center, Beauchamp decided to carry out a more carefully monitored experiment. He put people on a controlled, low-sodium diet, and indeed, they adapted.
BEAUCHAMP: In about four-to-eight weeks, the amount of salt that they found optimal in soup or crackers declined about 40 or 50 percent.
CHARLES: Beauchamp says this seems to show we can get used to food with less salt in it. So we could be healthier, and still enjoy our food just as much. The problem is, there's no easy way to make this happen. Consumers aren't captives who can be forced to adapt. And most of the salt that we eat comes in food that somebody else made for us, everything from bread to sandwich meat or salad dressing.
And the companies that make these products aren't going to cut salt from them if they think it will drive consumers away. Todd Abraham is senior vice president for research and nutrition at Mondelez International, which makes Ritz crackers and Wheat Thins and Oreos.
TODD ABRAHAM: We'll always make sure these products taste good, because if we produce products that are low-salt and consumers don't buy them, we actually haven't helped the issue with the American diet at all, because they'll go to a different product, which has higher levels of salt in it.
CHARLES: So it's a competitiveness issue.
ABRAHAM: Most definitely. I mean, we have to make products that consumers are willing to buy, versus the alternatives they have.
CHARLES: A couple of years ago, a committee of scientists from the National Academy of Sciences Institute of Medicine called on the government to help solve this problem with regulations. Regulations, the scientists said, could force all the food companies to bring down salt levels in unison. There would be no high-salt alternatives, and consumers would adapt.
Todd Abraham and most industry executives don't like that idea. They say regulations are impractical, and they're not necessary, because big food companies now are acting on their own. They are, slowly and silently, reducing salt levels in many processed foods. And they're hoping that consumers won't even notice. Dan Charles, NPR News.
INSKEEP: And this afternoon on ALL THINGS CONSIDERED, Dan explains how that happens, how companies are taking down the salt content so consumers don't notice.