The first well-controlled study to test whether salt added to your plate leads to premature death has come up with a clear answer. Yes, it does.
The lead author suggests leaving the saltshaker in the kitchen cupboard—or getting rid of it permanently— to reap substantial health benefits.
Should we take his advice? Not every doctor agrees.
The relationship between dietary salt intake and health has been the subject of debate since doctors in France observed patients with high blood pressure were high salt users. And that was way back in 1904!
Other previous studies examining salt’s relationship with mortality have produced conflicting results. Low accuracy in the way intake is measured is one reason. Another reason is that sodium in salt (sodium chloride) interacts with potassium and other minerals. Untangling the impact of salt alone on mortality is therefore extremely difficult.
Since salt added at the table accounts for between six and 20 percent of total salt intake and also reflects a person’s long-term preference for salty tasting foods and habitual salt intake, researchers from Tulane University, New Orleans, thought this would be a novel way of measuring the mortality effect.
Boosts Risk of Early Death by 28 Percent
For their study, published in the European Heart Journal in June, researchers analyzed data from 501,379 volunteers taking part in the UK Biobank. Over the course of nine years, 18,474 died prematurely, which the researchers described as dying before the age of 75.
Their findings showed that compared to those who never or rarely added salt, participants who always added salt to their food had a 28 percent increased risk of dying prematurely. At the population level this means one additional person in a hundred between the ages of 40 and 69 would die early.
Lovers of the saltshaker also had a lower life expectancy. At age 50 women lost 1.5 years and men had their life shortened by 2.28 years.
The additional risks from adding salt were reduced slightly among people consuming the highest amounts of fruits and vegetables. Professor Lu Qi, who led the study, wasn’t surprised “as fruits and vegetables are major sources of potassium, which has protective effects and is associated with a lower risk of premature death,” he said.
Although this was a well conducted study and took into account a vast number of factors that could affect the outcome, Professor Qi cautioned that the results need to be validated before any recommendations can be made.
As the first study of its kind, he’s right to be cautious. There are also reasons to be doubtful about his findings. One expert even thinks we should use more salt.
Salt Can Save Your Life
Last year, a study of salt intake in 181 countries, also published in the European Heart Journal, concluded that the higher the intake the lower the risk of all-cause mortality. Higher intake was also positively associated with healthy life expectancy.
Another study that tracked blood pressure readings in 2,632 adults over 16 years found both upper (systolic) and lower (diastolic) readings increased as salt intake declined. The lead researcher said, “for generally healthy people, we saw no evidence of harm in consuming the average American intake of 3.6 grams a day.”
A vocal critic of the negative view of salt is Dr. James DiNicolantonio, a leading cardiovascular research scientist and Associate Editor of the British Medical Journal’s Open Heart journal.
In his book The Salt Fix he presents a plethora of evidence to show the experts have it all wrong. He claims that our bodies evolved to consume salt. Too little salt leads to problems with the heart, kidneys, and thyroid, elevates cholesterol and insulin, creates dehydration and fatigue, lowers sex drive, and causes obesity. Far from reducing salt, we should consume more. It might, he claims, save your life.
While I’m not in agreement with Dr. DiNicolantonio, it is worth noting that salt doesn’t seem to harm the Japanese, French or Koreans who have high salt diets yet enjoy low rates of cardiovascular disease.
The 2020 to 2025 Dietary Guidelines for Americans recommends an upper limit of 2.3 grams of sodium each day. Yet Koreans, consuming 4.3 grams a day, have some of the world’s lowest rates of hypertension; so much so it’s called the Korean Paradox.
This debate over salt is clearly set to continue.