Sprinkle of Doubt on New York City's Salt Siege
Mayor Michael Bloomberg's war against salt has put him in the cross hairs of medical researchers, some of whom are sprinkling skepticism on the administration's dire warnings about sodium intake.
A new analysis by an internationally respected research body has cast doubt on the city's claims about the perils of a salty diet and raised questions about whether the city's health campaign will save lives.
Researchers, who compiled and reviewed seven randomized controlled trials of salt reduction, found little compelling evidence that eating more salt shortens lives. And one of the studies found that it's actually harmful for heart-failure patients to cut back on salt.
In the past year and a half, Mr. Bloomberg and New York City health officials have made salt a public enemy, seizing the issue with the same gusto that the administration devoted to snuffing out smoking. The mayor said he hoped to save 23,000 lives a year by persuading New Yorkers to consume 50% less sodium.
To reach that goal, the mayor has led a national effort to get restaurants and packaged-food manufacturers to use less salt. Last fall, officials plastered the city with ads warning of heart attacks associated with salt intake.
The most memorable of the images from the $370,000-campaign was a geyser of salt gushing from a soup can. "Too much salt can lead to heart attack and stroke," one of the ads stated in a grim, red font.
But unlike the mayor's crack-down on smoking, the city's claims about salt are drawing scrutiny from health researchers, who question whether the Bloomberg administration has exaggerated the known dangers of a salty diet.
Produced by the Cochrane Collaboration, an international network of scientists that conducts systematic reviews of medical research, the analysis found that people who went on salt-restriction diets didn't live any longer than people who maintained their normal eating habits.
"The Cochrane findings undermine the appealing assumption that the modest blood pressure fall caused by curtailing sodium intake will necessarily translate into cardiovascular protection," wrote Michael Alderman, a professor of medicine and editor of the American Journal of Hypertension, which published the review in its August issue.
It's drawn a dismissive reaction from Bloomberg officials, who say they have no intention of ratcheting down their anti-salt effort.
A spokeswoman for the New York City health department said the analysis had a "number of limitations" that "make the findings difficult to interpret" and pointed to a recent observational study that pointed to health benefits of less salt.
But Mr. Alderman noted that the bulk of evidence is far less conclusive and maintained in an interview that "there ought to be overwhelming evidence that you can do good" when developing a public-health campaign.
"The most demanding set of studies produced insufficient evidence of that good," Mr. Alderman said.
Write to Jacob Gershman at jacob.gershman@wsj.com