The Extraordinary 0.01 percent

I exposed the complete lack of science behind the government’s 40-year-long low-salt campaign in a previous Dispatch (“The Great Salt Scam”). And I’ve been warning people for years that trying to meet these guidelines may even be causing more harm than good. But as I mentioned yesterday, there’s more to say on this topic.

According to the 2010 government Dietary Guidelines, people should limit their salt intake to 2,300 mg per day. And people over 50 years old, and those with diabetes, hypertension, or chronic kidney disease should eat just 1,500 mg per day.

But a new study published earlier this month in the American Journal of Clinical Nutrition showed some interesting results.

Researchers reviewed data from the U.S. National Health and Nutrition Examination Survey (NHANES). The survey included two separate 24-hour dietary recall questionnaires. The researchers looked at the responses of over 12,000 people and came up with an average sodium intake.  

Of course, the problem with questionnaires like this is that there’s no way to validate the data. It relies entirely on information that comes from asking people to remember what they ate over the prior 24 hours. As I said yesterday, this is a notoriously faulty way of assessing dietary intake unless steps are taken to validate the data reported.

Still, the new analysis reached an amazing conclusion: The dietary guideline for sodium intended for most American adults (1,500 mg per day), is currently being met by less than 0.015% of the population.  

And don’t forget—people tend to underestimate the “bad” foods they eat. So had the NHANES study used a more effective method of collecting data, chances are, even fewer people would actually “measure up” to the government guidelines.

So what should we make of a supposedly critical dietary guideline that can be met by only one one-hundredth of one percent of the target population? Shouldn’t we all be dropping in the streets like oversalted sides of beef? Or perhaps our bodies know better than government bureaucrats about normal salt levels?

In my own practice of forensic medicine I see young, healthy women dying unexpectedly of “hyponatremia”—or low salt. Granted, such instances may be more attributable to an electrolyte imbalance resulting from various conditions (an eating disorder, dehydration, or epilepsy, for instance). But still—extremely low salt can cause acute, sudden death. High salt simply does not.

But, I digress.

The new study concludes that it would take “extraordinary efforts” to meet the current Dietary Guideline sodium recommendations.

Or maybe there is something extraordinarily wrong with this government guideline—and the lack of real science behind it.

“Reducing the sodium-potassium ratio in the US diet: a challenge for public health,” AJCN 2012; July 3 (epub ahead of print)