Reducing Sodium Intake to Reduce CVD Burden: AMA Report Published

Michael O'Riordan
Heartwire 2007. © 2007 Medscape
July 26, 2007 (Chicago, IL) – The American Medical Association (AMA) has now published the scientific report behind last year's recommendations calling for a reduction in the amount of sodium in processed and restaurant foods. Combined with education and improved labeling, individuals should be able to enjoy a lower-sodium diet without inconvenience or a loss of food choices, say the authors, but they note that in the continued absence of voluntary measures from the food and restaurant industry, new regulations will be required to achieve lower sodium concentrations.
"In the past, what people weren't fully cognizant of was the fact that most of the salt was coming from restaurant and packaged foods," author Dr Stephen Havas (American Medical Association, Chicago, IL) told heartwire. "The message we had been giving to the public, as well as the message the doctors had been giving to their patients--don't use salt at the table, don't use salt when you're cooking--was advice of very limited value, especially since 80% of people's salt was coming from restaurants and processed foods. Unless we pay attention to that, we are never going to reduce sodium intake."
The new report, from the Council on Science and Public Health, is published in the July 23, 2007 issue of the Archives of Internal Medicine [1].
A few dissenting voices still out there
In June 2006, as part of a campaign to reduce the burden of cardiovascular disease, the AMA published new recommendations to help reduce the amount of sodium in processed and restaurant food. The new guidelines were designed to the help change the way Americans thought about salt, as well as emphasize the importance of paying attention to the various sources of sodium in their daily lives.
The new recommendations urged the Food and Drug Administration to revoke the "generally-recognized-as-safe" status of salt and to develop regulatory measures to limit sodium in processed and restaurant foods. Over the next decade, the AMA called for a minimum 50% reduction in sodium in processed foods, fast-food products, and restaurant meals. The AMA also called for ways of improving labeling to assist consumers in understanding the amount of sodium in processed food and develop a marking system to warn of foods high in sodium.
Havas told heartwire that there has been some "reluctance" on the part of the food industry to adopt these recommendations, and as such, voluntary measures have been slow to arrive. The link between sodium consumption, high blood pressure, and cardiovascular disease is solidly established, said Havas, but some scientists, as well industry, have argued the evidence isn't fully there.
"The problem is that the case hasn't really been brought to the physician community in a good way, or to the public," he said. "Until the time we published the report last June, and it got out to the public by the media, people still thought there was a controversy, because these few scientists and the Salt Institute have kept trying to make it appear that the issue is not settled."
In the new report, the AMA points out that substantial public-health benefits can be gained from small reductions in sodium intake. A 1.3-g/day reduction in sodium, for example, translates into a 5-mm-Hg smaller rise in systolic blood pressure. Between the ages of 25 and 55 years, this small reduction would translate into an estimated 150 000 lives saved. The paper also notes that populations with an average sodium ingestion of less than 1400 mg/day have virtually no hypertension and show no progressive increase in blood pressure with age. In the US, average sodium consumption has been estimated to be 4000 mg/day per 2000 kcal, substantially higher than the 2300 mg/day recommended by the American Heart Association.
One of the more disturbing trends figures in the literature, said Havas, is the 55% increase in sodium intake in the US from the early 1970s to 2000, a trend he attributes to more and more people eating out, as well as larger portion sizes.
"We don't know if sodium intake is still increasing, but it's a huge concern," said Havas. "Until that figure was published, the knowledge of this was not out there in any big way. We assumed, because we were putting out these messages from the High Blood Pressure Education coordinating committee about sodium and the need to reduce sodium intake, that the public would be consuming less. However, we didn't recognize that we weren't giving quite the right message, because we didn't concentrate on processed and restaurant foods."
Dickinson BD, Havas S for the Council on Science and Public Health. Reducing the population burden of cardiovascular disease by reducing sodium intake. Arch Intern Med 2007; 167:1460-1468.