It’s not exactly a blood-pressure raising headline, which is probably why the new report from the Centers for Disease Control and Prevention is actually bears the alarming titled, High Sodium Intake in Children and Adolescents: Cause for Concern. The study will no doubt be hailed by public health advocates as proof that something must be done to bring America’s sodium intake in line with the recommendations of the CDC and other health originations. However, the report’s findings, when put into context of 50 years’ worth of research on global salt consumption aren’t alarming at all.
High sodium intake is associated with all sorts of nasty health problems—as the CDC was careful to note in the opening paragraph of its report. As NBC News put it:
Studies clearly show that eating a lot of salt can raise blood pressure — not in every single person, but in a significant percentage of the population. The latest survey of what kids eat shows that more than 90 percent of them are eating far too much salt…
According to the CDC, “U.S. school-aged children consumed an estimated 3,279 mg of sodium daily,” which is almost 1000 more milligrams of salt than the CDC recommends for children. Of course, what they aren’t saying is that kids aren’t eating more salt than they have in the past. When the CDC looked at adolescent sodium intake from 2003 to 2008 it found they were consuming the same amount: 3,300. In 2012 the American Heart Association warned that children ages 6-11 consumed an average of more than 3,000 milligrams a day and that boys between 12 and 19 years old averaged more than 4,000 milligrams a day! While I couldn’t find earlier studies on childhood sodium intake, it is likely that any chance in childhood consumption of sodium would be linked to any change in adult consumption and that has remained stable since the late 1950s.
The global rate of sodium is consistent—eerily consistent—across cultures and time, something the CDC doesn’t like to talk about. It appears that the amount of salt a person craves is physiologically determined and most human beings have a fairly narrow range of how much sodium they need. In 2010, researchers Bernstein and Willett of Harvard published a report that analyzed 38 studies published between 1957 and 2003 on the sodium intake of more than 26,000 participants. It found that even with Americans consuming more “processed” foods, sodium consumption levels stayed in a remarkably narrow range—the overall mean consumption being 3,526 milligrams per day.
In the same year, researchers at UC Davis led by David McCarron published their study that analyzed urine samples in 19,151 people in 33 countries over a 24-year period. The average daily sodium intake was 3,726 milligrams a day, across diverse populations and diets, and with no evidence of change over time. In a 12-year study of more than 13,000 people from Switzerland, also published in 2009, people averaged around 3,680 milligrams a day.
Yet, the CDC continues to push its recommendation that adults consume no more than 2,300 milligrams a day, despite the fact that humans globally tend to consume about 1,000 more milligrams than recommended. Additionally, there is ample evidence that even the strongest clinical interventions do little to alter the amount of sodium people consume. As my former colleague Dan Compton pointed out, numerous studies provide evidence for the idea that how much sodium a person needs is physiologically determined and they are unconsciously driven to meet that need:
Another study had used intensive dietary counseling to get participants to cut daily sodium intake to an average of 1,775 mg over four weeks. After that, the subjects, while still receiving counseling, were randomly split into two groups — one getting a sodium tablet, the other a placebo.
Those who got the placebo still raised their intake by nearly 1,000 mg, while those on the sodium tablet actually cut their dietary-sodium consumption to compensate.
These people didn’t know how much sodium they were getting — they unconsciously changed their diets to match what their bodies “knew” they needed.
Apparently, the CDC isn’t driven by evidence. It even rejected a study it commissioned from the Institute of Medicine, which found that reducing sodium levels below 1,500 milligrams a day (CDC recommends for about half the population) may be dangerous. Perhaps this quixotic battle to “rein in” America’s sodium consumption has more to do with politics than science. Hopefully, when it comes to nutrition the CDC and other agencies will heed the advice of David McCarron et al. who suggested this:
This scientific evidence, not political expediency, should be the foundation of future government policies, thus respecting the known and unknown scientific complexities surrounding sodium's role in health and disease.
Or, better yet, the CDC and other government agencies will butt out of our dietary decisions and Americans will take any of their dietary recommendations with several thousand grains of salt.