Over the course of the past decade or so, reducing dietary sodium has become a regular call to action. From consumers personally deciding to try to reduce sodium in their diets and companies creating lower-sodium versions of high-sodium staples to calls for the formal regulation of sodium in our food supply, we're seeing pressure on sodium everywhere.
More often than not, the call to action hinges on sodium's role in high blood pressure and heart disease, and large meta-analyses consistently recommend sodium reduction as an important public health intervention therein. What's not covered in those analyses is sodium's role in the "betcha can't eat just one" phenomenon of food hyper-palatibility and whether or not it has played a role in leading our society to eat roughly a meal of extra calories a day than we did in the early 1970s.
I think it probably has. But regardless of where sodium's primary risk comes from, before we get into the question of how we might effect its reduction, we need to consider the question of whether or not it's even reducible.
Looking to the medical literature for help, two papers jump out. The first came out of Harvard and looked at trends in American sodium consumption between 1957 and 2003. Now this wasn't dietary recall data, in which researchers called folks up and asked them how much sodium they were consuming; instead, this utilized the gold standard of measuring sodium excretion to determine levels.
Their counterintuitive finding was that despite enormous changes to our food supply (increased reliance on meals out, supersizing of portions and the rise of processed food), sodium consumption has not budged since the late 1950s.
The second paper, also utilizing sodium excretion data, similarly found that sodium consumption remained constant in the United Kingdom between 1984 and 2008 – again, contrary to what might have been assumed to have occurred during that time period.
These papers suggest that seemingly regardless of what and where we're eating, the amount of sodium in our diets remains surprisingly constant. In turn, that finding suggests that sodium-reduction strategies may prove to be quite challenging. If we manage to, for instance, regulate it down in our processed and restaurant foods, might that simply lead us to add more on our own?
[Read: Recipe for Health.]
From a blood pressure perspective, adding more on our own might make our sodium-reduction strategies moot: The link between blood pressure and sodium would necessitate a reduction in dietary sodium to decrease blood pressure; however, it's sodium's role in driving hyper-palatable, processed food consumption where there may still be benefit.
According to the U.S. Food and Drug Administration, 75 percent of our current dietary sodium consumption comes from restaurants and processed foods, and I can't help but wonder whether or not our sodium-reduction strategies would be better off focusing more on where our sodium is coming from rather than how much we're consuming.
If you'd like to reduce the sodium in your diet, rather than keep a running tally of how much you're actually consuming, why not try instead to determine what percentage of your diet comes from restaurants and boxes? Sure, there's data to suggest you might simply find other ways to add salt to your diet. But visit restaurants and consume processed foods less frequently, and I'd be willing to wager that you'll be far more likely to see health benefits than were you to simply fill your grocery cart with low-sodium versions of highly processed foods.
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Yoni Freedhoff, MD, is an assistant professor of family medicine at the University of Ottawa, where he's the founder and medical director of the Bariatric Medical Institute—dedicated to non-surgical weight management since 2004. Dr. Freedhoff sounds off daily on his award-winning blog, Weighty Matters, and you can follow him on Twitter @YoniFreedhoff. Dr. Freedhoff's latest book, The Diet Fix: Why Everything You've Been Taught About Dieting is Wrong and the 10-Day Plan to Fix It, will be published by Random House's Crown/Harmony in 2014.