Alternate headline: Nanny state hardest hit. After years of government warnings that Americans must lower sodium levels in their diet to avoid heart disease and strokes, a new study commissioned by the CDC finds that the 1500-mg level long championed by policymakers is not just wrong, but so low as to potentially cause health problems:
In a report that undercuts years of public health warnings, a prestigious group convened by the government says there is no good reason based on health outcomes for many Americans to drive their sodium consumption down to the very low levels recommended in national dietary guidelines.
Those levels, 1,500 milligrams of sodium a day, or a little more than half a teaspoon of salt, were supposed to prevent heart attacks and strokes in people at risk, including anyone older than 50, blacks and people with high blood pressure, diabetes or chronic kidney disease — groups that make up more than half of the American population. …
But the new expert committee, commissioned by the Institute of Medicine at the behest of the Centers for Disease Control and Prevention, said there was no rationale for anyone to aim for sodium levels below 2,300 milligrams a day. The group examined new evidence that had emerged since the last such report was issued, in 2005.
“As you go below the 2,300 mark, there is an absence of data in terms of benefit and there begin to be suggestions in subgroup populations about potential harms,” said Dr. Brian L. Strom, chairman of the committee and a professor of public health at the University of Pennsylvania. He explained that the possible harms included increased rates of heart attacks and an increased risk of death.
In fact, the recent data shows that even a slightly higher level than the current government recommendations might be too low:
One 2008 study the committee examined, for example, randomly assigned 232 Italian patients with aggressively treated moderate to severe congestive heart failure to consume either 2,760 or 1,840 milligrams of sodium a day, but otherwise to consume the same diet. Those consuming the lower level of sodium had more than three times the number of hospital readmissions — 30 as compared with 9 in the higher-salt group — and more than twice as many deaths — 15 as compared with 6 in the higher-salt group.
Another study, published in 2011, followed 28,800 subjects with high blood pressure ages 55 and older for 4.7 years and analyzed their sodium consumption by urinalysis. The researchers reported that the risks of heart attacks, strokes, congestive heart failure and death from heart disease increased significantly for those consuming more than 7,000 milligrams of sodium a day and for those consuming fewer than 3,000 milligrams of sodium a day.
There are physiological consequences of consuming little sodium, said Dr. Michael H. Alderman, a dietary sodium expert at Albert Einstein College of Medicine who was not a member of the committee. As sodium levels plunge, triglyceride levels increase, insulin resistance increases, and the activity of the sympathetic nervous system increases. Each of these factors can increase the risk of heart disease.
If this was just an academic exercise, it wouldn’t matter much in terms of public policy. That’s not what happens when it comes to health-related studies. Politicians seize on them to push intrusive regulations that hamstring consumers and businesses, and New York is one of the best examples of this. In fact, one state assemblyman attempted to pass a salt limit for restaurant cooking two years ago that followed the example of the trans-fat ban Mike Bloomberg imposed for New York City.
Properly used, these studies would allow people to make their own choices about their health, and keep government regulation from becoming obstacles to those choices. After all, as Woody Allen noted in Sleeper, we don’t know all of the benefits and demerits of the foods we eat now — and the recommendations might change significantly in the future (h/t Damien Bennett):
At the time this came out, remember that the government was recommending a low-protein, high-carbohydrate diet regimen for health. At that time, eggs were supposedly the big national health threat with their high levels of cholesterol. Today? A part of a healthy diet and a source of protein and unsaturated fat.
Update: Julian Morris has more on bogus public health scares at Reason, specifically on Bloomberg’s attack on sugary drinks.
Update: Corrected the title of the movie, which is Sleeper. Sleepers is a much different movie.