Bad Science: CDC Forced to Reverse its Recommendations on Salt

Mother may know best, but Uncle Sam certainly doesn’t.

In 1977, the federal government put a warning label on saccharine, claiming it caused cancer. It took only 20 years to to admit this was wrong. Then there’s the so-called Healthy Food Pyramid created by the USDA to advise Americans on the composition of a supposedly healthy diet. Although many still follow the recommendations of the food pyramid, it has since been questioned by researchers and nutritionist and even cited as a potential factor in America’s skyrocketing rate of obesity. Now we have another example of bad advice — government recommendations on sodium intake.

For years, public health advocates, politicians, and government agencies such as the FDA, and Centers for Disease Control and Prevention have been cajoling Americans to cut their salt intake and pressuring food makers to comply with salt-reduction programs.  Agencies recommended we cut sodium consumption to less than 2,300 mg a day. In May, the CDC was forced to admit this advice was wrong as well. A report commissioned by the CDC and conducted by the Institute of Medicine of the National Academies found no evidence to support this previous advice.

Over the last decade, studies on salt, many with conflicting conclusions, have called into question the commonly accepted wisdom that less salt is better. Some research has even concluded reducing sodium consumption too much might result in increases in mortality for certain groups of people. According to the report brief, the committee of researchers with the Institute of Medicine was tasked with assessing this new body of research on sodium and to come to conclusions about dietary recommendations for the general population.

The study, titled, “Sodium Intake in Populations: Assessment of Evidence,” found higher levels of sodium consumption were associated with increased risk of heart disease. But there was no evidence to suggest that consuming less than 2,300 mg of sodium was correlated with any increase or decrease in risk for heart disease, stroke or death. Furthermore the study found that reducing sodium intake to less than 1,840 mg a day could increase the risk of negative health outcomes for certain people.

“Recognizing the limitations of the available evidence, the committee found no consistent evidence to support an association between sodium intake and either a beneficial or adverse effect on health outcomes other than cardio-vascular disease outcomes (including stroke and CVD mortality) and all-cause mortality.” But the committee also concluded that “evidence from studies on direct health outcomes is inconsistent and insufficient to conclude that lowering sodium intakes below 2,300 mg per day either increases or decreases risk of CVD outcomes (including stroke and CVD mortality) or all-cause mortality in the general U.S. population.” The committee’s ultimate conclusion is that for most people, sodium consumption is not all that important a factor in managing their health risks. “We found no consistent evidence to support an association between sodium intake and either a beneficial or adverse effect on most direct health outcomes,” said Dr. Brian L. Strom, George S. Pepper Professor of Public Health and Preventive Medicine at the University of Pennsylvania, who chaired the committee that released the report.

So what does this mean? Many people will, undoubtedly, become frustrated with the repeated reversals on dietary recommendations. But this is simply the nature of scientific research. It takes years of good research and rigorous academic debate to come to conclusions about how the human body operates. And even then, those conclusions are –or at least they should be—readily re-evaluated and amended when new evidence is found. This lack of perfect knowledge isn’t a problem when individuals are allowed to examine the current body of evidence and choose whether the recommendations are appropriate for their unique situation. Problems arise when politicians or health advocates assume that one research paper constitutes gospel truth for every person and then attempts to coerce the entire population into complying with those recommendations. One person’s magic potion could be another person’s poison, and  both should be free to make that determination for themselves.