Blog | Thursday, May 29, 2014

Getting granular about salt

In my prior column I made the case that worries about consuming too little sodium are substantially moot in the world where most of us do our eating. Sodium is an essential nutrient, and it is, of course, possible to consume too little. In much of nature (of the terrestrial variety), salt deficiency is a legitimate hazard, and the reason why many animals will make a pilgrimage to a salt lick. All of us who have completed medical training have seen hyponatremia (low sodium levels in the blood) in people as well, and it’s a very unpleasant condition to say the least. While more often due to a metabolic abnormality than low salt intake, cases of hyponatramia, which can be life threatening, vividly demonstrate that too little sodium is not a desirable alternative to too much.

So yes, we can consume too little sodium. And yes, we are rather uncertain at this point about what exactly the ideal threshold is, and just how universally it pertains. But despite any such distillation of misgivings and doubts, the present problem is clear enough. Whatever the optimal intake of sodium is, most of us in the modern world are well above it, with blatantly adverse health effects to show for it. A large aggregation of data from diverse sources indicates that human health improves when sodium intake is dialed down from the levels that now prevail.

So, since too much salt is one of the many ways the modern diet is broken, consuming less is the relevant fix. My argument is not that every question has been answered, but that we are better served to head productively toward the sweet spot than to let worries about overshooting forestall such progress altogether. Perfect is the enemy of good, and less salt would be good for most of us.

All the more so because most of our salt intake reaches us courtesy of processed foods that tend to carry other liabilities as well. The longer the ingredient list of a packaged food, the more sodium it is likely to contain, but also the more sugar (under whatever array of aliases); the more colorings; the more flavorings; the more food chemicals; and the more calories. A focus on eating less salt is no more necessary than a focus on eating less added sugar, or saturated fat, or trans fat, or calories. Rather, eat more “good stuff,” and the nutrient details tend to take care of themselves.

While true, that’s rather vague, and it may also seem a bit Pollyanna. That won’t do for a public health pragmatist like me, so I suspect a bit more granularity is in order. That, then, is today’s mission: getting granular about salt reduction.

Virtually all debate about optimal sodium intake refers to levels well below 2,500 milligrams per day, so we may comfortably accept that as a non-contentious target, apt to do us good. If we superimpose that sodium level on the prototypical diet of 2,000 calories, it gives us 1.25 milligrams of sodium per calorie. If the foods we eat average more than 1.25 milligrams sodium per calorie, our diet will provide more than 2,500 milligrams per day. If salty foods pull our average up, we must rely on non-salty foods to pull it down, so we land somewhere in proximity to the 2, 500 milligrams total.

But what are the salty foods that pull our average up? The usual suspects no doubt come to mind: soup, condiments, and everything in the “salty snack” aisle of the supermarket. If that were the whole story, we’d be in much less of a pickle. Alas, it is not.

Consider that America, purportedly, runs on Dunkin’. So a typical American day might begin with Dunkin’s bacon, egg, and cheese breakfast sandwich. If it does, it starts out with 460 calories, and 1,200 milligrams of sodium. That’s 2.6 milligrams of sodium per calorie, or well over twice as salty as you want your diet to be on average. If breakfast is pulling average salt intake up, what is the chance that lunch and dinner, where the truly salty foods tend to cluster, will pull it down?

Lest you think I am cherry picking my examples, note that most of Dunkin’s other sandwiches, both breakfast and bakery, are more concentrated in sodium than the example I chose. And there’s no reason to pick on Dunkin’; McDonald’s Egg McMuffin delivers 840 milligrams of sodium in 300 calories.

But then let’s presume that you are far too fastidious to have a fast-food sandwich for breakfast. If instead you have a bowl of, say, the seemingly quite virtuous Grape-Nuts cereal, you are getting 290 milligrams of sodium per 210-calorie service. That is, you guessed it, more than 1.25 milligrams per calorie. Grape-Nuts is saltier than our diets should be on average. And no need to pick on Grape-Nuts, either; the same is true of Cheerios, Life cereal, and even Frosted Flakes. Almost the entire inventory of America’s most popular breakfast cereals is saltier than our diets should be on average.

From here, the news could readily go from bad to worse. The Center for Science in the Public Interest has published summaries of both processed foods and restaurant dishes that are not just highly concentrated in sodium, but in some cases deliver nearly a two-day supply (i.e., nearly 5 grams!) in just one dish.

But more bad news won’t help us, so let’s shake things up. Where is the good news?

You may be surprised. Consider, for instance, that Garden of Eatin’, one of my favorite chip brands (yes, I do think the nutritionally virtuous can occasionally eat chips!), offers yellow corn chips, ostensibly a salty snack, with just 70 milligrams of sodium per 140 calories. That’s just 0.5 milligrams sodium per calorie. So this so-called salty snack helps pull down, not up, the average salt level in our diets. Many other offerings in the salty snack aisle do the same. How can that be?

The matter reverts back to the overall degree of processing. The Garden of Eatin’ chips in question have just three ingredients: organic corn, oil, and sea salt. Breakfast cereals with much higher doses of salt taste less salty because other ingredients, notably sugar, mask the salt flavor. (They also taste less salty because our palates have acclimated to, and been desensitized by, the ridiculously high levels of salt and sugar in our diets. This process can be reversed!) When ingredients are few, and nothing obscures the taste of salt, it takes much less of it to impress our taste buds.

This is a generalizable theme. There are breakfast cereals made from short lists of wholesome ingredients that provide dramatically less sodium than the more processed popular brands. The popular Lucky Charms sports a long ingredient list that is not only home to at least 4 dyes and artificial flavors that help multi-colored marshmallows impersonate breakfast, but also provides cover for about 1.7 milligrams of sodium per calorie. So while sugar and chemistry are the obvious liabilities of this product, it is also far saltier than our diets should be on average. In contrast, one of my favorite breakfast cereals, Nature’s Path multigrain, has 1 milligrams of sodium per calorie.

Shorter, simpler ingredient lists are associated with less sodium in not just chips and cereals, but also breads, crackers, dairy products, snack bars, spreads, dressings, sauces, and even meats. These products tend to have less added sugar, too; to avoid harmful oils; to have more beneficial nutrients; and to help fill us up on fewer calories. Of course, to whatever extent you can prioritize foods with an ingredient list just one word long, apples, bananas, tomatoes, carrots, walnuts, broccoli, lentils, and so on, you reach the very pinnacle of this opportunity. Such foods don’t just help pull down our overall sodium intake, they help pull up the overall quality of our diets.

My colleagues and I developed, studied, published, and offer for free a food label literacy program called Nutrition Detectives designed to help kid and their parents trade up food choices in any given category. You can help yourself to the program if so inclined. Minimally, note that one of the 5 clues that constitute the program’s punch line is this: the shorter the ingredient list, the better. Better means much more than less sodium, but it tends to mean that into the bargain. For those with access toNuVal, the nutrient profiling system we similarly developed, studied, and published, higher scoring foods in any given category similarly offer better overall nutrition, and less salt as part of that formula. We have evidence as well that such trade-ups can be made using either approach without spending more money.

The copious excesses of sodium to which we are all exposed reside not just where we would expect them, but almost everywhere in the modern foodscape. The good news is that in all those same food categories there are alternative choices that are simpler, tasty, more nutritious, often no more expensive, and less salty besides. The very granular strategy of choosing foods with shorter ingredient lists allows for cutting out many superfluous grains of salt by way of improving overall nutritional quality. There should be no controversy in that.