Over the years, salt has gained a bad reputation in nutrition circles. Known variously as the “Silent Killer,” the “Hidden Killer,” the “Forgotten Killer” and even “the No. 1 Killer Worldwide,” it has been blamed for health problems ranging from high blood pressure and heart disease to obesity, diabetes and kidney failure.
But a growing number of medical and nutrition experts are questioning that dim view of salt, as well as federal guidelines that call for sharp limits to salt intake. One of the most visible is James DiNicolantonio (PharmD ’10), author of “The Salt Fix: Why the Experts Got It All Wrong—and How Eating More Might Save Your Life.”
“The bottom line is there’s never been a study that proves cutting salt intake reduces cardiovascular events and mortality,” says DiNicolantonio, a cardiovascular research scientist for Saint Luke’s Mid America Heart Institute in Kansas City, Mo., and clinical pharmacist. “In fact, low salt intake can actually be harmful to your health.”
DiNicolantonio, who also serves on the editorial boards of several medical journals, says that prevailing theories about salt are based on studies later shown to be flawed. For example, the massive Intersalt study of 1988, which involved 52 population centers around the world, found that blood pressure increased when sodium intake rose above 2,400 milligrams per day. That figure—the equivalent of 1 teaspoon— helped determine the U.S. Department of Agriculture’s 2,300-milligram recommended daily limit.
However, two decades later, statisticians found that the study’s result was distorted by four outlying data points. When those populations were excluded, the data shifted to a clear downward slope for blood pressure as salt intake increased—suggesting that for the vast majority of populations, more salt was actually beneficial.
DiNicolantonio, 30, has been suspicious of low-salt orthodoxy since his high school days, when he discovered that upping his salt intake improved his performance as a wrestler and cross-country runner. After following his great-grandfather, mother and brother into the UB School of Pharmacy and Pharmaceutical Sciences, and then working in the community, his suspicions deepened.
“Patients were coming to me dizzy and fatigued on salt-depleting diuretics and complaining their doctors were telling them they couldn’t add salt to their food,” he says. One patient was also on an antidepressant that further lowered sodium levels. DiNicolantonio sent her back to her doctor, who, finding her to be dangerously dehydrated, halved her diuretic while advising her to eat more salt. Her condition improved dramatically. “That was a powerful moment early on in my career that seriously made me question the low-salt advice,” he says.
That advice includes the American Heart Association’s recommendation of less than 1,500 milligrams daily—an amount which, DiNicolantonio points out, is lost in sweat in one hour of exercise. He recommends anywhere from 3,000 to 6,000 milligrams per day for a healthy person. (The average American consumes 3,200 milligrams daily.)
“Compared to normal salt intakes, low salt intakes are associated with an almost doubling of cardiovascular mortality and around a 40 percent increase in all-cause mortality,” says DiNicolantonio. “We never demonized an essential nutrient before—only salt,” he adds. “Meanwhile, the huge increase in refined sugar in the American diet parallels the rise of chronic diseases like hypertension, diabetes and obesity.
“Turns out we demonized the wrong white crystal.”