A vital yet misunderstood mineral
By Matt Held
“What’s the deal with salt these days?” I exclaim into the mic. “It’s a necessary mineral for human life, but it’s killing us? Make up your mind!” The audience is silent because it’s not really even a joke and my Jerry Seinfeld impression is dreadful.
Despite being just one sodium ion and one chloride ion stuck together by magical forces, its use in our bodies cascades into incredibly complex pathways and behaviours, making it far more fascinating than its simple molecular makeup. Plus, it has fascinating historical significance to the development of human civilisation and continues to impact us today.
Salt Throughout History
The past several decades have seen salt painted as the enemy; however, this wasn’t always the case. Salt was historically highly valued—in fact, the word salary comes from the Latin root word salarium, with sal meaning salt. A salary was paid to Roman soldiers so that they could buy salt to support themselves and their families. Some historians note they may have actually just been paid in salt. Why was it valued so highly? People couldn’t pop down to the local shop and grab a bag of ice for their cooler when they took their drinks to the beach, so salt was used to preserve food, allowing it to be stored and consumed for longer periods. This was critical to human expansion—fresh foods can only last so long before they are inedible. By preserving them with salt, you can extend the shelf life and travel further distances, set up new villages and discover new things all thanks, in part, to a preserved, stable food supply.
Two more linguistic facts: the word salad comes from the Latin word salata, meaning salted, which first came about when vegetables were salted to preserve them. The phrase “worth one's salt” comes from the payments to Roman soldiers, essentially saying if they were performing well, they were worth the salt they were being paid.
What Does Salt Do for the Body?
When salt is added to food and dissolved, it breaks down into its component ions—sodium and chloride. Salty is one of the five basic human tastes (including sour, sweet, bitter and umami) and it’s sodium that primarily makes something “salty.” Sodium is essential to more than just a tasty avocado toast; it’s a necessary element for our survival. According to the Harvard School of Public Health, the body “requires a small amount of sodium to conduct nerve impulses, contract and relax muscles, and maintain the proper balance of water and minerals.” In other words, things that we would not be alive without.
Both sodium and chloride are two of the most highly concentrated electrolytes found in our bodies, which help to maintain electrical potential in cells, regulate the transfer of fluids and nutrients into and out of the cells, maintain proper pH levels and stimulate stomach acid. Again, things we would not be alive without. Notice a trend here?
So what happened? When did salt go from hero to zero? Why did we all grow up being told salt is bad for us? The science is all over the place. Several studies have shown that a high salt diet is associated with high blood pressure and possibly stomach cancer. However, it’s important to note that many of these studies are observational. It’s hard to conclude if a high salt diet is causing the damage or if the high salt diet indicates a poor diet in general that is causing issues. An extensive review of seven studies done in 2011 found that although high salt intake may correlate with high blood pressure, there was no correlation between high salt and heart disease and death. On top of this, several studies found a low salt diet correlated with increased LDL cholesterol and insulin resistance (which ironically leads to higher blood pressure). Yet digging into further studies, reducing the sodium in a diet for overweight individuals led to a significant decrease in blood pressure. Still, the effects were minimal on those at a healthy weight. Very complex!
Salt is Just One Part of the Puzzle
Many have suggested that it is not strictly the salt itself that is the issue, but high salt being an indication of nutritionally void foods (which is very common in the American Diet). Take a double quarter pounder, for example. The burger contains almost 60% of the recommended sodium in just 740 calories. But it also has nearly 100% of your saturated fat and 55% of the cholesterol recommended in a 2000-calorie diet. These foods are also highly processed and stripped of vitamins and minerals. If you grab a medium Coke with that burger, you’re taking in 111% of your recommended added sugar for the day, which in addition to the 16% daily value of added sugar that’s oddly in the burger, gets you to 127% of your added sugar in two food items. But yes, salt is the problem here…
It’s estimated that 40-60% of the typical American’s diet contains highly or ultra-processed foods with minimal nutritional value. These high-salt food items are easy to access, tend to be lower in cost and can be addictive. These dietary tendencies add an entire socioeconomic angle that goes beyond my ability to rant about as a food scientist. However, it shows that it’s way more complex than just ‘reducing salt’ in our diet; our food system needs an overhaul, and salt cannot be target number one.
Taking off the tinfoil hat for a second, much like caffeine, individuals have different tolerances to salt, and you should tailor your intake based on your lifestyle. Sodium and chloride are two of the highest-level electrolytes typically found in the bloodstream. If you’re an athlete, you may need a higher salt intake than someone more sedentary to stay hydrated and keep your muscles functioning. Maybe you get this from your double quarter pounder. Perhaps you get it from an electrolyte mix—I’m not here to judge. I just want to bring awareness to the next time you look at a nutrition facts panel and see high sodium—consider what other baggage that product may, or just as importantly, may not be bringing along with it and tailor your intake accordingly.
Matt Held is MUD\WTR's Senior R&D Manager specialising in food science.
Photo by Faran Raufi on Unsplash
