Even though there are reports of possible danger from extremely low sodium intake, Harvard experts agree: Less salt is better.
Don’t believe everything you hear—especially if you’ve heard you no longer have to worry about sodium, the too-much-is-bad-for-you part of salt.
Last spring, many media reported the too-good-to-be-true news that salt isn’t all that bad for your heart, and that lowering sodium intake too far could even be harmful.
The source of these news stories was a report from an Institute of Medicine (IOM) committee. The panel was asked to look at whether people who reduced their intake of sodium to the very low levels recommended by the American Heart Association really did have better health outcomes. Does reducing sodium to less than 1,500 mg a day really result in less disease and longer life?
The panel found very few studies that measured health outcomes in people who managed to get their sodium intake down to 1,500 mg or less. They did find European studies of people getting an unusually extreme fluid-restriction treatment for heart failure not used in the United States. When these people also reduced their sodium intake to very low levels, their heart failure got worse.
“So we saw no evidence for better outcomes in people going from low to very low levels of sodium,” says Nancy Cook, a professor of medicine at Harvard Medical School. Dr. Cook is a clinical trial expert at Harvard-
affiliated Brigham and Women’s Hospital and was a member of the IOM panel.
Take with a grain of salt
Just because the IOM panel couldn’t link better outcomes to very low salt consumption doesn’t mean it isn’t good for you. In fact, people who do achieve very low sodium levels have significantly lower blood pressure.
“Reducing sodium to the lowest level should lower blood pressure and reduce coronary artery disease risk,” Dr. Cook says. “But it is very hard to get down to those levels [1,500 mg per day]. People may have been told to go to those levels, but few achieve them.”
Dr. Dariush Mozaffarian, associate professor of medicine and epidemiology at Harvard Medical School, has studied the link between salt intake and heart disease.
“From a public health point of view, I think there is enough evidence that lower salt consumption is better, but we cannot be 100% convinced,” he says.
And what of those European studies suggesting that very low sodium may actually harm people with heart failure?
These studies are based on people who received more aggressive treatment than one normally finds in the United States. These studies may not be relevant to the great majority of people in the United States.
As further evidence that very low salt consumption is not harmful, the Yanomamo people of the Amazon rain forest get by on just 200 milligrams (mg) of sodium a day, and have little heart disease.
|Salt in common foods:|
Most of our salt from certain foods, because we eat so much of them—particularly the American Heart Association’s Salty Six:
1. Cold cuts and cured meats.
Most cooked meats would spoil in just a few days without added salt. Even foods that would otherwise be considered healthy may have high levels of sodium. Deli or prepackaged turkey can contain as much as 1,050 mg of sodium per serving.
2. Breads and rolls.
Just one slice
Yes, it’s full of cholesterol and fat. And it’s also salty. Solution: eat less pizza. When you do have a slice,
Lean, skinless grilled chicken is fine – unless the bird has been injected with a sodium solution. Beware chicken nuggets, which are loaded with sodium.
Putting cold cuts on bread can surpass your daily sodium limit in one shot.
The average American consumes about 3,500 mg of sodium a day. The AHA recommends a much lower target—the “very low” level of 1,500 mg per day. Official U.S. guidelines suggest the same level for over half the population: people over age 51, African Americans, and people with diabetes, kidney disease, or certain other chronic conditions. Everyone else is urged to get sodium intake below the “low” level of 2,300 mg per day.
Way too much salt the norm
Table salt is about 40% sodium
Only 1% of Americans consume as little as 1,500 mg of sodium per day, and only 9% have sodium levels below 2,300 mg per day, Dr. Cook says.
The IOM panel was asked to evaluate outcomes-based evidence for lowering sodium consumption from 2,300 mg to 1,500 mg per day.
“What was absolutely missing from the message is that going from the 3,500 mg of sodium per day, where we are now, to 2,300 mg per day is better,” Dr. Mozaffarian says.
“The level of sodium consumption is too high in the United States, and it is clear that reducing sodium leads to less coronary artery disease,” says Dr. Cook.