The Salt
2:28 am
Thu December 20, 2012

The Paradox And Mystery Of Our Taste For Salt

Originally published on Thu December 20, 2012 10:37 am

Salt is one of those dangerously tasty substances. We add the magical crystals of sodium chloride to almost everything that we cook or bake, and according to many public health experts, we add too much.

They want us to cut back, to lower our risk of heart attacks or strokes.

Yet when you really start looking for ways to do this, you run into a paradox and a scientific puzzle.

First, the paradox. Too much salt may kill us, but our bodies need some of it to survive.

"If you don't keep up your sodium level in your body, you will die," explains Paul Breslin, a researcher at the Monell Center, a research institute in downtown Philadelphia devoted to the senses of taste and smell. (Breslin also teaches at Rutgers University.)

At the same time, Breslin continues, "there's no question that people who have high salt intakes are at risk for a heart attack and stroke and death, and that lowering their salt intake will save lives. In Finland, when they lowered the salt intake, stroke and heart attack rates went way down, and mortality went way down."

There are skeptics who discount the relevance of the Finnish example. The average person in Finland, at that time, was eating a lot more salt than Americans typically do. The anti-salt campaign brought that level down to around the global average. The skeptics say, for most of us, that average level of salt consumption may be just fine.

But both the World Health Organization and the U.S. Centers for Disease Control and Prevention are calling on people around the world to cut salt consumption even more. The average American, they say, should cut their intake of salt by a third.

This won't be easy, because people like salt. It makes many foods taste better.

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.

On the one hand, Breslin says, a massive international study of salt consumption around the world, conducted in the 1980s, suggests maybe we're born with it. "All across the planet, with a few exceptions, most people consume more or less the same amount of sodium," Breslin says.

The exception is people who can't easily get salt, such as isolated tribes in Amazonia. Everywhere else — from small villages in China to Chicago, people consume similar amounts — much more than our bodies need.

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, director of the Monell Center, says the first evidence for this came from stories told by doctors who ordered patients with high blood pressure to switch to a low-sodium diet. Their patients reported that "it was awful at first, but after a while, it wasn't so bad," Beauchamp says. Their taste sensors seemed to adapt, a little bit the way our eyes adapt to a dark room.

In fact, Beauchamp says, after they did that for a while, "when they went back to their normal food, it was too salty."

Beauchamp decided to carry out a more carefully monitored experiment to study this. He put people on a controlled, low-sodium diet, and they did adapt. "In about four to eight weeks, the amount of salt that they found optimal in soup or crackers declined by 40 or 50 percent."

It seems to show that we can get used to foods 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.

Most of the salt that we eat comes via food that somebody else makes for us, such as bread, sandwich meat and salad dressing, and the companies that make those products aren't going to cut salt from them if they think it will drive consumers away.

"We'll always make sure these products taste good," says Todd Abraham, senior vice president for research and nutrition at Mondelez International, which makes Ritz crackers, Wheat Thins and Oreos. "If we produce products that are low-salt and consumers don't buy them, we haven't helped the American diet at all, because they'll go to a different product that has higher levels of salt."

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, they pointed out, could force all the food companies to bring down salt levels in unison. There would be no high-salt alternatives, and consumers would eventually adapt to the new taste.

Food industry executives like Abraham don't like that idea. They say that such regulations are impractical. They also argue that regulations aren't necessary, because big food companies now are acting on their own. They are reducing salt levels, slowly and silently, in many processed foods. They're hoping that consumers won't even notice.

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

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. Transcript provided by NPR, Copyright NPR.