In addition to containing too much sugar, many processed foods contain too much salt, or, more appropriately, too much sodium. Sodium is an essential mineral. Sodium chloride is particularly effective as a preservative, a seasoning agent and a flavor enhancer. Among the essential minerals the Daily Value (DV) that appears on the Nutrition Facts statement is the upper limit of what we should consume. For all other minerals the DV is the lower limit of we should consume. The DV for sodium is 2300mg (roughly 1 teaspoon of table salt). The average consumption for an American runs at least 3300mg (almost 1 1/2 teaspoons). Recommendations for consumers with high blood pressure is a limit of 1500mg or about 2/3 of a teaspoon). A large proportion of the American public is susceptible to high salt intake, but not everyone is susceptible.
The CDC (Centers for Disease Control and Prevention) alerts us that 77% of the salt we consume comes from processed and restaurant foods. Unfortunately, it is very difficult to find out how they made these calculations. Apparently they based these numbers on large surveys of consumers that were made in 2011-2012, but it is not clear how they know how much salt was added in the home or with the salt shaker. CDC describes bread as the number one source of salt in the American diet. Many consumers don’t think of bread as being a processed food, but by CDC’s definition it certainly qualifies. Almost all commercial breads, not just sliced white bread, tend to be high in sodium. See how a simple sandwich can add up to more than half the %DV for sodium for an individual in a day.
A major goal in the food industry is salt reduction. It is not as easy as it might seem. When I was teaching, two teams in my graduate class, Flavor Chemistry and Evaluation, conducted projects one semester on salt reduction. One team looked at the detection limits of added salt in cream of mushroom soup. They found that a panel could detect differences in both normal- and low-salt versions of the product at levels as low as 74mg (3%DV) of added salt suggesting that consumers are very sensitive to slight differences in the amount of salt added. The other project looked at reducing salt in a chicken product. The team of graduate students went through several formulations (scientific versions of a recipe) before they found a highly acceptable one that was low in salt. The secret was in a clever manipulation of spices. The problems with substituting various spices for salt are (1) it adds more ingredients to the list, (2) tends to increase costs as salt is cheaper than most spices, and (3) many individuals tend to be very fussy about the taste of specific spices in their food.
Developers of products for food companies are usually food scientists, chefs or a combination of the two. They are under pressure to lower salt content and reduce the number of ingredients in formulated products (ones with many ingredients) without any loss of flavor quality. There has been a government-inspired program to gradually and silently reduce the amount of salt in processed food, assuming that consumers will not be able to tell the difference. Companies look for technological ways to lower salt content, but they are unwilling to unilaterally disarm if their competitor does not go along as a company will lose market share because of noticeable differences in taste and flavor. One trick used by developers of products for restaurants which do not have to declare their ingredients is to substitute monosodium glutamate (MSG) for sodium chloride (table salt) as MSG provides more flavor at a lower sodium content than table salt. Another difficulty with lowering the sodium content is that salt, in its role as a preservative, slows the growth of microbes that spoil the food or make it unsafe1.
The answer many food pundits tell us to solve the too-much-salt problem is to cook at home because we know how much salt we are adding. It makes perfect sense. If processed food is where we are getting all our salt, just avoid processed food. But do we really know how much salt we are adding in terms of mg or %DV per serving? I don’t make those calculations when I cook, and I suspect that most cooks do not as well. Then, in estimating serving size, do we use the one given in a recipe or do we actually measure out how much is consumed including seconds? I rarely add salt to the dishes I prepare at home even when a recipe calls for it. When I view a promising recipe from the internet or even from a cookbook that promotes “healthy” alternatives, I am frequently surprised at how much salt is included. Michael Pollan obviously does not concern himself with how much salt he is adding. His recipe for barbequed pork shoulder in Cooked results in 44%DV for sodium per serving which increases to almost 60% when including the sauce.
America has a salt problem, but it is more complex than avoiding processed food. The single processed food to avoid that would make the biggest difference would be bread. Tips for salt reduction are readily available on the internet. Frequently, kosher, sea or Himalayan pink salts are offered as alternatives to regular table salt. Such alternatives contain more beneficial trace minerals than regular table salt, but they also contain almost as much sodium. To gain the benefit of the trace minerals, one needs to consume way too much sodium. Alternative salts are usually crystalline and do not pack as tightly as table salt. Thus, a teaspoon of kosher salt, for example, contains a little less sodium than a teaspoon of table salt. These alternative salts may offer a culinary advantage, but their use is unlikely to greatly reduce the amount of sodium consumed.
My solution is to eat less bread for two reasons. First, bread is the most fattening food I eat. My favorite snack is a slice of crusty Vienna bread slathered with Benecol®. Not that buttered bread is that calorie dense, but I have trouble eating just one large slice from the center of the loaf. Second, bread is an unlikely source of hidden salt. I still eat sandwiches when I go out to eat, but I don’t eat many sandwiches at home.
A shout out to Adrian and Christina for their assistance in helping me recall information about their team projects.
Next week: Revisiting some of the previous posts.
1.Taormina, P.J., 2010. Implications of salt and sodium reduction on microbial food safety. Critical Reviews in Food Science and Nutrition 50:209-227.