We know this question seems heretical. For decades Americans have been exhorted by health professionals to lower their sodium intake to reduce blood pressure and improve heart health. The idea that a low salt diet might actually produce negative outcomes is blasphemous.
For years, the American Heart Association has urged people to limit sodium intake to less than 1,500 mg daily:
The AHA Recommendation:
“For optimal heart-health, the American Heart Association recommends people aim to eat no more than 1,500 milligrams of sodium per day. That level is associated with a significant reduction in blood pressure, which in turn reduces the risk of heart disease and stroke.”
A New Study Contradicts Traditional Wisdom:
Research published in The Lancet (online, May 20, 2016) adds to the growing awareness that too little or too much sodium can be hazardous to your health. Unlike many diet studies, this investigation did not rely upon people’s memories about what they ate. Scientists actually measured the amount of sodium in the morning urine to better approximate salt consumption. There were over 130,000 individuals from 49 countries. The participants were followed for roughly four years. The data suggest that a low-salt diet may actually raise the risk for heart attacks, strokes, heart failure and death.
The scientists found that people who consumed between 3,000 and 6,000 milligrams of sodium daily had the lowest risk of cardiovascular complications or death, whether or not they had high blood pressure. Keep in mind that this “sweet spot” is between two to four times the amount of sodium the AHA recommends.
For those with hypertension, both lower and higher levels of sodium were associated with increased mortality. People with normal blood pressure were at greater risk of cardiovascular events only if they were consuming low amounts of sodium.
What Happens When You Consume a Low Salt Diet?
With very low levels of sodium, the body cranks up its production of stress hormones like renin, aldosterone and catecholamines, all natural compounds that can increase the risk of cardiovascular events. The authors of The Lancet study point out that:
“Several studies have shown that increases of renin, aldosterone, and catecholamines are all associated with increased cardiovascular disease events and mortality.”
The AHA has seemingly not considered the physiological impact of their low-sodium recommendation.
The researchers point out that most of the world’s population consumes more than 3,000 mg of sodium daily. (Americans average about 3,400 mg of sodium per day.) Although this level is more than twice what the AHA recommends, there was no evidence of harm when people consumed this amount. Only people with hypertension seemed to get into trouble when they consumed over 6,000 mg of sodium a day. Based on The Lancet research one could reasonably conclude that people with high blood pressure should not pig out on pretzels, potato chips or other highly salted foods. But the new results also suggest that a low salt diet could be harmful for such individuals.
Shooting The Messenger (The Lancet):
The American Heart Association has criticized this new study. The organization is sticking to its recommendation of less than 1500 mg of sodium per day for everyone. The AHA argues that, “the public should not be confused by the flawed study.” An official with the World Health Organization went further and said The Lancet should not have published the study in the first place. His exact quote: “It is with disbelief that we should read such bad science published in The Lancet.”
Not surprisingly, these public health officials have criticized the methodology of The Lancet study. We won’t bore you with the details of the point-counterpoint arguments. You can read the back and forth debate for yourself at MEDPAGE TODAY.
Not The First Study Contradicting the Low Salt Diet:
A study published in the American Journal of Hypertension on April 2, 2014, analyzed data from 25 previous research papers. The article was titled “Dietary Sodium Restriction: Take It with a Grain of Salt.” This meta-analysis concluded that a low-salt dietary strategy is associated with a higher risk of death. In the authors’ own words:
“There is no conclusive evidence that a low sodium diet reduces cardiovascular events in normotensive and pre-hypertensive or hypertensive individuals. On the contrary, there is sound evidence that a low sodium diet leads to a worse cardiovascular prognosis in patients with systolic congestive heart failure or type 2 diabetes mellitus…Advising low sodium diets seems misguided and potentially dangerous and illustrates the problem of guidelines based on flawed studies using surrogate measures.”
The Institute of Medicine (IOM) issued a report that was published in JAMA Internal Medicine (online, Oct. 28, 2013) that found there are no data demonstrating benefit from the CDC or American Heart Association’s low-sodium guidelines. The Institute of Medicine is now called the Health and Medicine Division (HMD) of the National Academies of Sciences, Engineering and Medicine. It represents the best and the brightest in American medicine. When such a prestigious group of researchers and clinicians says that the scientific literature does “not support recommendations to lower sodium intake within these subgroups [‘patients with diabetes, hypertension, chronic kidney disease, or preexisting cardiovascular disease’] to 1500 mg/d or less” you can believe them.
The Bottom Line from The People’s Pharmacy:
Old beliefs die hard, especially when prestigious public health organizations like the American Heart Association or the CDC constantly proclaim that a low salt diet is good for your health. We find it disappointing that such organizations cannot seem to admit that they might have made a mistake. Instead, they circle the wagons and reject the new evidence.
If we are to believe the new (and old) research, there are no significant problems associated with an average salt intake around 3,000 mg daily. People with high blood pressure should not exceed 6,000 mg of sodium per day, but that is a lot of salt. Most individuals will not consume that much unless they really work at it. Restricting your salt intake to less than 1,500 mg of sodium a day may indeed pose health problems. For that reason The People’s Pharmacy will continue to resist the AHA recommendations.
Should you wish to read more about this complicated issue, here is a link to an article we wrote even before the new Lancet research was published titled: “Is a Low Salt Diet Dangerous to Your Health?”
You may also find this article of interest: The New Salt Wars: Why Doctors Can’t Agree on Cutting Sodium.