Let's Ask Marion: Kidney Stones In Kids: Time To Shake Off The Salt?

(With a click of her mouse, EatingLiberally’s kat corners Dr. Marion Nestle, NYU professor of nutrition and author of Pet Food Politics, What to Eat and Food Politics:)

Kat: Last Tuesday's New York Times reported that kidney stones, "once considered a disorder of middle age, are now showing up in children as young as 5 or 6." One of the primary culprits appears to be excess consumption of salty processed foods. The problem is especially bad in the "so-called stone belt, a swath of Southern states with a higher incidence of kidney stones."

You noted in What To Eat that because the food industry--especially the snack food sector--relies so heavily on salt to make its products taste better, it's pretty easy to exceed one's recommended daily allowance for salt. The Center For Science in the Public Interest calls salt "perhaps the deadliest ingredient" in our food supply, because excess salt consumption is a major cause of heart disease and strokes.

That's why the CSPI has been petitioning the FDA for years to revoke salt's "GRAS" status--i.e., "generally recognized as safe," and reclassify it as a food additive, as well as establishing limits for its use.

But the government is notoriously reluctant to advise Americans to consume less of anything, as you noted earlier this month in the Journal of the American Medical Association. Meanwhile, the big food corporations are trying to score reduced-fat, low-sodium brownie points by adopting new, improved nutrition standards for their products under the "Smart Choices Program," which will supposedly make it easier for consumers to make healthy selections at the supermarket.

With our kids up to their hineys in brine, do these kinds of voluntary measures do enough to address the problem, or is the CSPI justified in calling for greater regulation of salt?

Dr. Nestle: Pity the poor food industry. First the makers of junk foods are under siege over sugars and childhood obesity and now they have to deal with salt-induced kidney stones.

We are talking junk foods here. Without sugars and salt, nobody would buy this stuff. That, at least, is what food company executives tell me. When they reduce the sugar or salt level below the “bliss” point, sales drop. This, of course, is because we are so accustomed to a junk food diet that it takes more and more sugars and salt to stimulate our taste receptors. Try two or three weeks on a low sugar, low salt diet. Do that and you will soon see that processed foods now taste unbearably sweet or salty.

Food companies are responding to pressures to reduce calories, saturated fat, sugars, and salt with their Smart Choices Program. This is designed to replace the PepsiCo Smart Spot, the Kraft Sensible Solutions, and other such company self-endorsements of “better-for-you” junk foods—an oxymoron if I have ever heard one. The way these programs work is that each company sets up its own nutritional criteria for qualifying for the logo.

The Smart Choices program works the same way except that participating companies have agreed on a unified set of nutritional criteria. These, as you can see on their website, are not especially stringent.

The salt standard is a good example. It is the same as that of the American Heart Association—a remarkably generous 480 mg of sodium per serving, or 20% of the Daily Value maximum. Salt is 40% sodium and 60% chloride, which means that 480 mg sodium corresponds to 1.2 grams of salt per serving. This, for example, allows salty soups to qualify.

But if you want to try to eat less salt, just try and get food companies to cooperate. Processed foods are by far the largest source of salt—90%--in American diets. What you add at the table hardly counts. This is because food companies are addicted to salt. Adding salt is a great “eat more” strategy. Salt heightens flavors and extends shelf life. It is cheap. Even better, it binds water and makes foods weigh more, and companies can charge more for heavier packages. Unfortunately for them, just about every scientific group that has examined the evidence says salt raises the risk of high blood pressure, stroke, heart disease—and now premature kidney stones--at least in a significant fraction of people. And now even kids are getting salt-induced kidney stones.

To me, the salt issue looks like one in which I have no options except not to eat processed or restaurant food at all. This is completely backward. If people want their food to taste saltier, nothing stops them; all they have to do is pick up a salt shaker. But the rest of us have no choice. Someone else has already made the decision for us. Salt, and usually lots of it, has already been added to the foods we are served or sold. As I see it, the responsibility lies squarely with food companies. I wish they would lower the salt in their products, starting right now. The generous salt allowances in the Smart Choices program won’t help much.

What that program really is about is preemption of the traffic signal approach for labeling food products, under serious consideration in Australia. Food companies hate the idea. Too many of their products will qualify for red (don’t eat) and yellow (once in a while) labels.

One final thought: Why am I thinking that lawyers will be most interested in the relationship between salty products marketed to children and kidney stones?