Is eating too much salt truly harmful? Mainstream medical advice and routine doctor visits may have convinced you that this is a clear-cut “yes,” but the science is anything but uniform. So why isn’t that reflected in common clinical practice?
The salt controversy does more than raise questions about how much salt is too much; it points to the very heart of a little-discussed issue: that much of the medical information we receive isn’t based on scientific consensus, despite the tone of definitive and certainty in statements made by key voices, including our doctors.
We’ve all gotten the message that we tend to eat “too much” salt—and that too much salt is a bad thing. Doctors, dieticians, and health associations have long cautioned that consuming excess sodium can hinder kidney function, raise blood pressure, increase the risk of cardiovascular disease, and even harm sleep quality.
Recognizing that, for most people, processed food is a major source of sodium, the U.S. Food and Drug Administration (FDA) announced in October 2021 a new plan to encourage manufacturers of packaged foods to cut down on added salt in their products. The FDA set a new goal for average salt intake of 3,000 milligrams per day, a 12 percent drop from the American average of about 3,400 milligrams per day.
However, the Dietary Guidelines for Americans, produced by the U.S. Department of Health and Human Services and the U.S. Department of Agriculture, recommend that adults limit sodium intake even further, to less than 2,300 milligrams per day, or about 1 teaspoon of table salt.
Newer research in animals reveals that excess salt may affect the mind as well as the body. Too much salt may raise stress levels, in turn affecting behavior (at least in mice), according to some studies.
One such recent study, performed at the University of Edinburgh in Scotland and published this month in the journal Cardiovascular Research, found that, in mice, a diet with too much salt raised stress hormones in the body.
The researchers found that a high-salt diet increased the levels of the stress hormone glucocorticoid by 75 percent. In addition, not only did resting stress hormone levels increase in the mice, but their hormone response to environmental stress was also double that of mice that followed a normal diet.
“We know that eating too much salt damages our heart, blood vessels and kidneys. This study now tells us that high salt in our food also changes the way our brain handles stress,” study co-author Matthew A. Bailey, professor of renal physiology at the University of Edinburgh’s Centre for Cardiovascular Science, said in a statement.
A paper published this year in the journal Neuroscience & Biobehavioral Reviews examined a number of studies to quantify what’s known about the effects of salt on behavior in animals.
The review authors, of Kent State University in Kent, Ohio, wrote that although excess salt intake is a well-known risk factor for cardiovascular diseases, until now “relatively little has been explored about how it impacts behavior, despite the ubiquity of salt in modern diets.”
The research tested for behavioral changes such as anxiety and aggression in mice with high-salt diets. It was found that excess salt intake in the animals’ adulthood affected their spatial memory and “fear expression.” Early-life high salt intake was shown to increase their locomotion and impede social and spatial behavior.
The study authors wrote that these findings show that an “expanded study of salt’s effects will likely uncover broader behavioral implications.”
Is Salt Really So Bad?
James DiNicolantonio, a doctor of pharmacy, objects to what he calls the “low-salt dogma” and believes that salt has been unfairly demonized.
He claims that our bodies drive us to consume about 3,000 milligrams to 4,000 milligrams of sodium per day in order to remain in homeostasis, “an optimal state in which you put the least amount of stress on the body.”
DiNicolantonio told The Epoch Times that among salt intake studies performed on humans, every one “has an inherent flaw.”
“Almost every study does not give the exact same diet with the only difference being the level of salt intake,” he said. “Typically, what [researchers] do is they give more fruits and vegetables, [a diet] which just so happens to be lower in salt, and then they sort of extrapolate the benefits … and you can’t necessarily extrapolate that.”
In his book “The Salt Fix: Why Experts Got It All Wrong and How Eating More Might Save Your Life,” DiNicolantonio, who’s a cardiovascular research scientist at St. Luke’s Mid America Heart Institute in Kansas City, Missouri, argued that the vast majority of us don’t need to monitor our salt intake. He believes that salt restriction is harmful and that too little salt can make us crave sugar, leading to weight gain and Type 2 diabetes.
In fact, low-salt diets may have created the American epidemic of high blood pressure, DiNicolantonio wrote. In South Korea and other parts of the world, people routinely consume more than 4,000 milligrams of salt each day and yet have very low rates of heart disease and hypertension.
For most people, DiNicolantonio claims, eating more salt can improve energy, sleep, fitness, and even fertility and sexual function. He argued that “until the low-salt dogma is successfully challenged, we’ll be stuck in this same perpetual loop that keeps our bodies salt-deprived, sugar-addicted, and ultimately deficient in many critical nutrients.”
For animals, he pointed out, “there are no dietary guidelines, of course—no medical directives to create a conscious effort to restrict salt intake.” Except for those with certain medical conditions, DiNicolantonio stated that we don’t need to worry about “hitting salt overload,” since our bodies take care of any excess. A low-salt diet “indicates a crisis for the body, not a recipe for optimal health,” he wrote.
An Ongoing Controversy
Researchers at Columbia University and Boston University in 2016 conducted a “metaknowledge analysis” of what they called “the salt controversy.” The analysis, published in the International Journal of Epidemiology, looked at 269 reports published between 1978 and 2014 that examined the effects of sodium intake on cerebro-cardiovascular disease or mortality.
The researchers found that 54 percent of the reports supported the hypothesis that reducing dietary salt leads to population health benefits. One-third (33 percent) didn’t support this hypothesis, and 13 percent were inconclusive.
So although scientists have long disagreed about the benefits of lowering salt intake, public health messages regarding salt seem to not reflect this uncertainty, the researchers noted.
“The divide between the uncertainty in the scientific literature about the potential benefits of salt reduction in populations and the certitude expressed by decision makers involved in developing public health policies in this arena is jarring,” they wrote.
“Assuming that all parties involved have the best interests of science and public health in mind, this controversy raises questions about the production of knowledge in population health science and how that production influences public health practice.”
The researchers found that report authors were 50 percent more likely to cite papers that reflected their point of view, whether they believed that salt reduction was beneficial or not. Moreover, just a few prolific researchers produced most of the work in the field and seemed to be unaffected by the work of researchers who came to different conclusions.
“We found that the published literature bears little imprint of an ongoing controversy but rather contains two almost distinct and disparate lines of scholarship, one supporting and one contradicting the hypothesis that salt reduction in populations will improve clinical outcomes,” the authors wrote.
Public health officials, it seems, may have chosen to amplify the findings of only one part of the body of research produced on this topic, rather than acknowledge that there have long been two “sides” to the salt controversy.
DiNicolantonio offered practical advice for those concerned about salt intake.
“If you’re someone who’s consuming a whole food diet mainly made up of whole, nutritious foods—meat, vegetables, fruits—you’re going to be getting a very low amount of salt and you’re probably going to need to add some back to get you to a normal intake,” he said.
“Whereas if you’re someone who’s eating mostly processed foods … you’re probably already getting enough salt,” he said.
“Salt is an essential mineral. There’s going to be an amount that will be not enough, just like any mineral. There will be an amount that’s too much, just like any mineral, and there’s an optimal intake. Optimal intake seems to be a normal intake of salt. So not high, not low, but allowing your body to consume the salt that it inherently seeks out, which is basically how we treat thirst for water.”