Let’s settle this once and for all.
Even though both play several essential roles in our health (the brain needs sugar for energy, and muscles need salt to contract, for example), they can also cause a wide variety of health problems when consumed in excess, says Niket Sonpal, D.O., assistant professor at Touro College of Osteopathic Medicine in New York.
So which of these vices have a greater impact on our health, and why? Let's investigate.
It's not so much naturally-occurring sugars (like those found in fruit) that experts have a problem with as it is refined and added sugars. "Milk and 100 percent fruit juice, for example, contain natural sugars and calories, but they also provide nutrients, such as vitamins, minerals, protein (in milk), and polyphenols (in juice)," says Texas-based registered dietitian Kaleigh McMordie. Sugary beverages like soda and sweet tea, on the other hand, provide sugar and calories with little nutrition. The same goes for the majority of grab-and-go snack foods that surround us on the regular—they don't provide any nutritional benefits (like fiber, protein, or vitamins and minerals) unless they're stripped and then added back in later. Not surprisingly, overconsumption of these products can lead to obesity and nutrient deficiencies in one fell swoop, says McMordie.
"All sugars, regardless of how they're labeled—white sugar, high fructose corn syrup, cane sugar, evaporated cane sugar, brown sugar—have a similar effect on the body in raising blood sugar levels, causing the production of insulin," says Murdoc Khaleghi, M.D., medical director of WellnessFX. The body releases insulin in order to move sugar out of the blood and into the cells to use it as energy.
Generally, this process is pretty seamless, but when you're consuming excess amounts of sugar, your body's fat storage skills go into overdrive. The uptick in insulin production can lead to insulin resistance, forcing the body to create more insulin, which then stores more fat, according to Khaleghi. Over time, insulin resistance and the subsequent weight gain from excessive sugar consumption can lead to the development of type 2 diabetes, which can increase your risk for glaucoma, is a leading cause of kidney failure, and a is major risk factor for heart attack and stroke.
Worse, consumption of excess sugar, particularly refined sugars, can lead to changes in the body's metabolism and excessive inflammation, which can eventually segue into a variety of chronic diseases. "Certain kinds of sugar molecules, called fructose, are only processed by the liver," says Rachel Head, R.D., certified diabetes educator for One Drop. "When the liver is overwhelmed by processing too much fructose, a metabolic chain reaction can occur, with several studies linking this reaction to increased risks of abnormal cholesterol levels, high blood pressure, fatty liver disease, metabolic syndrome, and heart disease."
The human body needs salt to regulate fluids and carry electrical charges between cells. However, "while the effects of sugar are becoming increasingly understood, how salt affects our health is more debated," says Khaleghi. "For most healthy people, a moderate amount of salt is easily processed, and actually required by the body, while excess amounts may contribute to long-term health issues." Current dietary guidelines recommend that Americans consume less than 2,300 milligrams of sodium daily (one teaspoon). However, most people take in an average of 3,400 milligrams of sodium (the difference of one-third of a teaspoon, to put it into context), according to the Centers for Disease Control and Prevention.
For many years, experts believed sodium caused fluid retention in the body, and a buildup of pressure in blood vessels, leading to high blood pressure. Uncontrolled blood pressure can lead to major health problems, such as heart attack and stroke, as well as kidney and vision problems. However, the link between salt and high blood pressure has been under increased scrutiny. A 2014 study of over 8,000 French adults found that salt consumption wasn’t associated with systolic blood pressure in men or women. The study writers said that the link we assume exists between salt and blood pressure is “overstated” and “more complex than once thought.” A 2016 Women’s Health story on salt reported that there is no reliable proof that sodium actually contributes to blood pressure or the cardiac issues associated with it—rather, studies over the years have shown conflicting results about the mineral’s connection with cardiac problems.
“For a regular healthy person, salt isn't necessarily detrimental when consumed in moderation,” McMordie says. She however adds that some populations are more sensitive to salt—such as people over 50 and people who already have high blood pressure—making a change in sodium affects them more than others.
A big problem with excess salt, McMordie says, is that the majority of it comes from processed and restaurant foods rather than the salt shaker. "These foods are typically also higher in fat and calories, and provide fewer nutrients than fresh foods prepared at home," says McMordie. This can lead to weight gain, among other health issues besides high blood pressure.
Neither are particularly dangerous so long as they're consumed in moderation, but head-to-head, excess sugar has more of a negative impact on your overall health, says Head. McMordie agrees: “Salt is essential for the body to function properly. Sugar is not.” A 2014 review in the journal Diabetology & Metabolic Syndrome also found that sugar can increase the negative affects of salt, too. Insulin orders your kidneys to retain sodium—and the more insulin the body produces, the more water and sodium the kidneys retain. The result? High blood pressure.
To keep your sugar and salt intakes in check, focus on nutritious sources of carbs, such as whole grains, milk products, and fruit, says McMordie, and steer clear of foods that contain refined sugars and processed ingredients. Case closed.