The problem with that theory, says the New York Times' John Tierney, is that science doesn't back it up. In fact, science -- the latest research -- says exactly the opposite, that salt is good for both your physical and emotional health. A recent clinical trial put heart patients on two diets, one restricted sodium levels by a third, the other with normal sodium levels. The normal-sodium group did better. What's more, another recent study showed depression triggers in rats with salt deprivation. And the problem with the theory is that it's a theory; making New Yorkers (and, if Bloomberg and Frieden are successful, the entire U.S.) subjects of a great and foolhardy experiment.
While the NYC Department of Health cites the AMA and "authorities throughout the world" as evidence of its belief that cutting salt by a quarter industry-wide will "lower health care costs and prevent 150,000 premature deaths every year," Tierney points out that the evidence are, rather, unconnected dots that have never been scientifically linked. There is the evidence that reducing salt also lowers blood pressure; this has been shown to be true, on average, but not true for everyone (some people actually have a blood pressure increase upon reducing sodium intake), and the effect is both small and without causal link to overall health. Just to be clear: there is no clear scientific evidence, despite decades of research, that reducing salt saves either health costs or prevents heart disease.
Tierney is full of accusatory questions. "Dr. Frieden has predicted that people "won't notice the difference" if salt is gradually reduced, but how can he be sure? What if they respond by eating more food, or a different mix of foods and stimulants? What if the food industry turns to salt substitutes that cause new health problems?" he asks. At the heart of his criticism is another great experiment with the health of Americans and, by its influence, the western world at large: the demonization of dietary fat.
I, for one, am rather tired of being subjected to whatever is the latest great idea of the self-appointed ministers of health (that switch to soybean oil is so not helping us). And I'm certainly not going to reduce my salt intake; salt is one of the great joys of my life. It's only one of the reasons I avoid packaged and processed foods and cook my own from whole food ingredients (and lots of delicious sea and mineral salts from around the world). But, as much of the U.S. gets the majority of its food pre-packaged and cooked by food manufacturers and restaurants, if Bloomberg and Frieden are successful, we'll all be headed, 300 million lab rats, toward a future with less salt, even more depression, more heart problems, and the health costs to accompany those conditions.