Five phony public health scares: activist misinformation harms Americans.

• Author: Bailey, Ronald
• Position: Columns

Health activists, nutrition nannies, medical paternalists, and just plain old quacks regularly conjure up menaces that are supposedly damaging the health of Americans. Their scares range from the decades-long campaign against fluoridation to worries that saccharin causes cancer to the ongoing hysteria over crop biotechnology. The campaigners' usual "solution" is to demand that regulators ban the offending substance or practice. Here are five especially egregious examples of activist misinformation.

1. Americans should consume no more than 1,500 milligrams of sodium per day, in order to reduce everybody's risk of heart disease, strokes, and high blood pressure.

   You hear this one all the time. The American Heart Association recommends consuming less than 1,500 milligrams of sodium per day. A June 2013 report by the Center for Science in the Public Interest asserted, "Immediately reducing average sodium consumption levels to between 2,200 mg to 1,500 mg per day would save about 700,000 to 1.2 million lives over 10 years." These nutrition nannies have been urging the U.S. government to lower the upper limit of daily recommended sodium intake to just two-thirds of a teaspoon of salt.

   But a May 2013 study by the Institute of Medicine calls those longstanding recommendations into question. Contrary to years of anti-salt dogma, consuming less than 2,300 milligrams of sodium a day may actually harm people suffering from congestive heart failure. There was also "no evidence for benefit and some evidence suggesting risk of adverse health outcomes" if the person with a low-salt diet has diabetes, chronic kidney disease, or pre-existing cardiovascular disease.

   "The evidence on health outcomes," the report concluded, "is not consistent with efforts that encourage lowering of dietary sodium in the general population to 1,500 milligrams per day."

2. Vaccines cause autism.

   In 1998 the British researcher Andrew Wakefield claimed in The Lancet that he had identified an association between vaccination against measles, mumps, and rubella (MMR) and the onset of autism. Thus was launched one of the more destructive health scares of recent years, in which tens of thousands of frightened parents refused to have their children vaccinated. Anti-vaccine cheerleaders such as the actress Jenny McCarthy fanned those fears.

   Years of research and numerous studies have thoroughly debunked this scare. For example, the Institute of Medicine issued a 2011 report, "Adverse...