Food Science and Sodium

According to conventional wisdom, consumer health is adversely affected by the high sodium content of foods. Consequently, finding ways to reduce sodium intake has been getting a  considerable amount of attention. In addition, the Institute of Medicine’s “Strategies to Reduce Sodium Intake in the United States” motivated the U.S. Dept. of Agriculture to alter the Dietary Guidelines for Americans, recommending a reduced daily sodium intake of less than 2,300 mg for some Americans and less than 1,500 mg for others. This prompted many food manufacturers and foodservice operators to proactively seek out salt substitutes and adjust the sodium content of foods. But could these efforts be premature or even unnecessary?

Two studies published in 2011 appear to dispute research in this area. In one of the studies, “Fatal and Nonfatal Outcomes, Incidence of Hypertension, and Blood Pressure Changes in Relation to Urinary Sodium Excretion” (JAMA, May 4, 2011), European researchers determined that sodium intake had no effect on the development of high blood pressure and, more importantly, that a low sodium intake was strongly associated with death from cardiovascular disease. The other study, “Effects of Low-Sodium Diet vs. High-Sodium Diet on Blood Pressure, Renin, Aldosterone, Catecholamines, Cholesterol, and Triglyceride (Cochrane Review)” (American Journal of Hypertension, November 2011), reached a similar conclusion. The meta-analysis demonstrates that a low-sodium diet (less than 2,760 mg) appears to reduce blood pressure only marginally and increase the levels of cholesterol, fat, and hormones—all of which elevate the risk of heart disease.

These two studies are part of a mounting body of research that casts doubt on the U.S. government’s guidelines for sodium intake. To some extent, these developments could benefit the food industry: Despite the furtive reduction of the sodium content of food products over many years, consumer taste preference for salt remains high. Many manufacturers have struggled with consumer acceptance of the taste and flavor of reduced-sodium formulations. This has even caused some food manufacturers to add sodium—in the form of salt—back into their product formulations.

A uniform reduction in the sodium content of food is not an effective strategy. To the contrary, research indicates that single-nutrient initiatives (e.g., low-carb diets, low-fat diets, etc.) are counterproductive. Rather than relying predominantly on the recommended approaches to sodium reduction by national research centers such as the Institute of Medicine, perhaps future sodium reduction initiatives should be based more on the evidence, experience, and expertise of food industry professionals.

Many food scientists believe that a food composition database collecting nutrition content data on a range of key nutrients such as sodium, potassium, iodine, calories, fat, sugar, and fiber would be useful in attempting to reduce the sodium content of foods. A sodium-monitoring program to determine national taste preferences of consumers might also be beneficial. And a more complete understanding of the sodium levels in various American populations would be highly valuable.

Each of these strategies involves investing time and effort in determining the taste preferences of different demographics and monitoring their sodium levels. Such investments would enable food manufacturers to develop a variety of low-sodium products that would appeal to divergent tastes rather than uniform low-sodium products produced in response to regulatory requirements based on health risks.

The food industry needs a regulatory framework that supports sodium reduction rather than mandates it, allowing food and nutrition scientists time to investigate what works and what doesn’t work. Food scientists have spent an inordinate amount of time developing and promoting numerous low-sodium products that never leave supermarket shelves. At this point, establishing realistic targets for sodium levels in key food categories before issuing mandates seems like a more credible approach to reducing sodium content. Perhaps food scientists and technologists could reveal what they learn from reformulating products and the effects on quality, taste, and consumer acceptance. And maybe manufacturers could be persuaded to share the successes and failures of their sodium-reduction strategies so that the industry as a whole can avoid repeating ineffective tactics.

The current approach to sodium reduction is not effective as consumers eat more salt today than ever despite steady reductions in the sodium content of food. And as more studies emerge that dispute the detrimental effects of high dietary sodium on health, continuing down the current sodium-reduction path seems counterproductive. The solution may or may not be in a food scientist’s test tube, but we have a significant role to play in working with others to identify better options.

Roger Clemens , Dr.P.H.,
IFT President, 2011–2012
Chief Scientific Officer, Horn Company, La Mirada, Calif.
[email protected]