A recent New York Times article reported that Michael Bloomberg, the mayor of New York City, has announced that the city is starting a “nationwide initiative to pressure the food industry and restaurant chains to cut salt intake by half over the next decade.” The city has published data that this public policy experiment will lower health costs and prevent 150,000 premature deaths every year.

But where exactly is this data coming from? There is a strong following in the medical world for the anti-salt campaign, citing salty diets as a direct contributor to high blood pressure, and the associated heart problems. The logic, then, is that altering the public’s diet will reduce the number of morbidities and mortalities such as strokes and heart attacks. But the studies that suggest this connection may not be the most reliable works on which to base a complete overhaul of New York’s eating habits. In fact, most of the notable drop in blood pressure associated with a decrease in salty foods is observed in patients already suffering from hypertension. Furthermore, conflicting studies have reported a rise in blood pressure in response to less salt, or, more commonly, no change at all.

Without conclusive data to back his claims, it seems that Bloomberg is unethically engaging his citizens in a research experiment that may in fact be harmful to their health. The Times article cites studies that report numerous consequences of lowering salt intake, including anhedonia, a symptom of depression, an increased rate of hospitalization, and even death. What these conflicting reports tell us is that the effects of salt intake must be studied further, in a controlled and safe environment, and not with the heavy hand of sweeping legislation.

Enrolling an entire city in a giant experiment raises quite a few issues from a bioethical standpoint. Where are the consent forms? The IRB approval? Acknowledgement of risks and side effects? How about voluntary enrollment? As in all research, the experimenter cannot possibly be sure that the effects he predicts will come about. When an entire city is involved, it then becomes much more important to ensure safety and ethicality of such endeavors. In the 1990’s, there was a nationwide sweep to reduce the intake of fats, before clinical trials yielded any conclusive data. Interestingly, what we saw was an increase in the rate of obesity, as people were eating more “low-fat” foods that contained harmful ingredients, and switching their calorie intake to carbohydrates. It’s very possible that this anti-salt campaign will end in a similar story. If Bloomberg chooses to promote this venture as a public health policy, and not as a legislative experiment, it must be firmly founded in conclusive empirical data.

While it is indeed likely that the mayor has the people of New York’s best interests in mind, I do not think that an ill-informed and indiscriminate legislation is best serving their needs. An awareness program about the possible effects of salt on blood pressure, or dietary guidelines that promote healthy eating habits, would be a safe first step, until science can definitively declare salt as dangerous. As a final thought, I wonder whatever happened to letting people make their own choices about food. What’s next, issuing a warning label on pints of Ben and Jerry’s? Come on, Bloomberg. Take a page from Marie Antoinette, and “Let Them Eat Salt!”

– Libby Greismann