Salt Wars

not all about sodium

Salt = bad, right?  Maybe not so much.  The nutrition world has another controversy* that’s got the Food Police up in arms – the suggestion that cutting back on salt isn’t necessarily going to result in Health Utopia.

Salt is sodium chloride, and it’s the sodium part of that molecule that’s linked to increased risk for hypertension.  Specifically, excess intake of sodium.  We actually need sodium.  It’s critical for fluid balance, and it works with that other critical mineral, potassium, to keep the fluids in our cells in balance with the fluids outside our cells and in our blood.  Criticizing American’s high sodium (from salt) intake has become a holy ritual for certain in Food Police community.  Recently, US dietary guidelines suggested we get even less sodium that previously allowed: a mere 1500 mg/day, which is equivalent to less than 1 teaspoon of salt.

Most of the sodium in our diet comes from processed food.  It’s added by manufacturers, to give an appealing flavor that will have consumers coming back for more purchases.  People who eat little or no processed food likely have a drastically lower salt intake than people who rely on it all day long.  Most of the research that supports the link between hypertension and salt intake goes like this:

  • take people with high sodium intake who rely on processed food
  • change their diets drastically – remove the processed food, add more fresh fruits and vegetables, etc.
  • measure blood pressure changes
  • Voila – blood pressure goes down.  OBVIOUSLY it was because they ate less salt.

Not so fast: they also ate more potassium, which is clearly linked to lower risk for high blood pressure.  They ate less processed food, so they also ate fewer additives.  They ate more fiber, and probably less fat, as well as more of all the other vitamins, minerals and anti oxidants present in vegetables and fruit.  And if the subjects happened to lose weight on this new diet, that would have lowered blood pressure, regardless of diet.

In fact, the DASH diet, recommended for lowering blood pressure, is exactly that diet: heavy on vegetables, fruit and whole grains, high in potassium and high in fiber.  The lower sodium content is just one of many key differences that could affect blood pressure.  Claiming people on the DASH diet have lower blood pressure only because of the lower sodium intake is a false conclusion.   Here is how you prove that sodium alone is responsible for high blood pressure: you take people on a high sodium diet from processed foods, and you feed them nothing but the exact same processed foods minus the salt.  No other changes.  Then you see if a lower sodium processed diet alone will change blood pressure.  This would be difficult to do.  Probably impossible.  Those foods don’t exist and even if they did, people wouldn’t stick to that diet, because it would taste extremely bland.

The current controversy started with a study on sodium excretion, which was published in the Journal of the American Medical Association.  Excess sodium is excreted by the kidneys.  When researchers compared sodium excretion to risk for cardiovascular events, they found that people with lower sodium excretion had more adverse events, the complete opposite of what they expected.  It suggested that lower sodium intake was associated with higher risk.  The researchers concluded that blanket recommendations for everyone to drastically cut back on salt intake were not justified.

Predictably, a screechy firestorm of protests erupted from the entrenched nutrition community, who don’t like their true beliefs challenged by unpleasant facts (See: vitamin D controversy.  Just a decade ago, entrenched nutrition “experts” took great delight in mocking the few researchers who were sounding the alarm bell).  I’m not suggesting this study proves anything either, except that sodium dogma needs to be questioned and investigated more thoroughly.

Sodium is a complicated issue for humans: it makes food taste better; we need it for health; it’s a key component of sweat which is important for cooling off in these very hot days of summer.  And processed foods rely on it, perhaps too much, to boost flavor.  I suspect the sniffy attitude about salt intake is just another excuse to attack the food industry.  In the Food Police world, we’re all home all day everyday, cooking three little meals from scratch from pricey fresh local foods.  Everyone has leisure time for that, and no other obligations, like jobs.  And everyone wants to be home cooking every single day.  Right?

If you have high blood pressure, there are several lifestyle and diet changes that will help lower it:

  • lose weight
  • get more exercise and physical activity.  Move!
  • eat vegetables and fruits and whole grains every day, at every meal
  • eat fewer sugar-sweetened foods and beverages
  • use fewer processed and convenience foods, especially salty snacks

Simply switching to “low sodium” versions of processed food, without making these other changes, isn’t going to help much.  Switching to sea salt isn’t going to help either.  It’s still salt, although clever food marketers have managed to give it an undeserved Health Halo.

*that other controversy: saturated fat may not be causing heart disease after all, so why do some nutritionists continue to harp on it?

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