Swedish researchers have found that eating excessive amounts of salt is linked with clogged arteries, which is known to be associated with increased risks of heart attack and stroke, in a new paper published in the European Heart Journal on March 31.
This is the first study to examine the association between a high salt intake and atherosclerosis, the process of the narrowing of the arteries with plaque deposits, blocking blood flow to the heart and brain.
Study author Jonas Wuopio of Uppsala University’s Clinical Research Center said that “the association was linear, meaning that each rise in salt intake was linked with more atherosclerosis.”
The study involved over 10,000 Swedish participants aged between 50 to 64 years. The researchers analyzed the link between increases in salt intake and atherosclerosis through urine tests and 3D images of the heart arteries.
Each 1,000 mg rise in sodium excretion was associated with a three to four percent higher amount of plaque in the arteries.
The findings applied even at normal blood pressure levels, suggesting that salt could be damaging even before the development of hypertension.
“Interestingly, the results were consistent when we restricted our analyses to participants with normal blood pressure (below 140/90 mmHg) or to those without known cardiovascular disease,” Wuopio said.
“This means that it’s not just patients with hypertension or heart disease who need to watch their salt intake.”
“The results reinforce the advice from the World Health Organization (WHO) and other medical societies to minimise salt intake to about a teaspoon a day.”
The WHO has identified reducing salt intake as one of the most cost-effective measures that countries can take to improve health outcomes.
Consequently, its members have agreed to reduce their population’s salt intake by a relative 30 percent by 2025.
For example, Australia’s leading voice in nutrition and dietetics, Dietitians Australia, says that “most Australians eat more than the recommended amount of salt” and warns about its links to high blood pressure, heart disease, and other health problems.
But, other experts, including a doctor of pharmacy and cardiovascular research scientist James DiNicolantonio, object to what he calls the “low-salt dogma” and have attempted to shatter this reputation of salt.
He said 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 his book “The Salt Fix.”
He found that 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.
“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,” he said.
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.”
“Allow your body to consume the salt that it inherently seeks out, which is basically how we treat thirst for water,” he advised.
In a bid to cut Americans’ salt consumption, the Food and Drug Administration (FDA) recently said it was proposing a rule to allow the use of salt substitutes in everyday foods.
On March 24, the FDA proposed to change over 20 everyday items ranging from cheese and frozen peas to flour and canned tuna.
“Most people in the U.S. consume too much sodium. The majority of sodium consumed comes from processed, packaged, and prepared foods, not from salt people add to their food when cooking or eating,” Susan Mayne, the director of FDA’s food safety and nutrition division, said.
In 2016, researchers at Columbia University and Boston University 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 salt leads to 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 not to reflect this uncertainty.
Public health officials appear to 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.