In honor of the recent “March for Science“, I have decided to review a scientific assertion that is completely settled.

Salt is bad for you because it raises blood pressure. A sample of this consensus is on the website for the Centers for Disease Control and Prevention, focused on salt safety:

Most Americans Should Consume Less Sodium

Most of the sodium we consume is in the form of salt, and the vast majority of sodium we consume is in processed and restaurant foods. Your body needs a small amount of sodium to work properly, but too much sodium is bad for your health. Excess sodium can increase your blood pressure and your risk for a heart disease and stroke. Together, heart disease and stroke kill more Americans each year than any other cause.

…CDC is working at the national, state, and local levels to help reduce sodium in the food supply. CDC’s approach to sodium reduction includes supporting and evaluating ongoing initiatives to reduce sodium, providing technical assistance to the public health community, expanding the scientific literature related to sodium reduction, collaborating with stakeholders, and educating the public.

While our government is busy regulating food manufacturers and creating dietary alarm among consumers that the salt they enjoy will kill them by raising blood pressure and causing cardiovascular disease, new research indicates something quite different.

So different, it is completely opposite! From The San Diego Union Tribune:

In another blow against decades of accepted medical wisdom, one of the most prestigious, long-running studies reports that lowering sodium intake doesn’t reduce blood pressure.

The study also implies that most Americans are consuming a perfectly healthy amount of salt, the main source of sodium. But those who are salt-sensitive, about 20 to 25 percent of the population, still need to restrict salt intake.

Consuming less than 2,500 milligrams of sodium daily is actually associated with higher blood pressure, according to the Framingham Offspring Study report, given today. The American Heart Association recommends consuming no more than 2,300 milligrams of sodium daily, equal to a teaspoon of ordinary iodized table salt.

Surely, the researchers behind this must be salt harm deniers:

…The study is an offshoot of the groundbreaking Framingham Heart Study. Both are projects of the National Heart Lung and Blood Institute and Boston University.

The new report was delivered in Chicago during the Experimental Biology meeting by Lynn L. Moore, an associate professor of medicine at Boston University School of Medicine.

The report directly contradicts advice from the American Heart Association, which recommends consuming less than 1,500 milligrams of sodium a day to reduce blood pressure and risk of heart disease.

I have covered the continued revisions of consensus in dietary science extensively for Legal Insurrection:

Time and time again, the “experts” have had to walk back theories built upon politicized science, government agendas, and regulatory intervention. Meanwhile, thousands of doctors have made good-faith recommendations that may have hurt the patients they were suppose to heal, and millions of Americans have made diet choices that may have actually done far more harm than good.

Dietary science appears to be as stable as food fads that make their way into the culture (gluten-free being the latest craze). While this this may be the most unsettled science of all, the example of consensus science built around salt demonstrates how fallacious this approach to sound research and its application to our lives actually is.