excrete salt, Laffer says. “But the kidneys, in hypertension, may not excrete salt appropriately. They may hold onto it.” That can lead to problems ranging from swollen ankles to fluid buildup around the heart and lungs.
Salt also can threaten the brain by damaging blood vessels and raising blood pressure, which is a major risk factor for stroke. It also might change the behavior of the brain stem, which helps regulate salt balance and blood pressure.
Scientists are just grasping some of the ways salt works.
Recent studies show salt affects the immune system, leading to inflammation that could be behind heart disease and other problems, Elijovich adds.
His Vanderbilt colleagues also are examining how salt might affect bacteria in the gut. The investigation is new, Laffer says, but evidence points to gut bacteria having a role in salt-induced inflammation and high blood pressure.
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It affects everyone differently.
Blanket statements about salt and health can be tricky. The root mechanisms of how salt affects the body aren’t fully understood.
Some people who don’t have high blood pressure can eat salt without seeing their blood pressure increase. Others may have “salt sensitivity,” where even moderate salt intake triggers a higher blood pressure.
But the simple fact is that for most people, cutting salt is a healthy thing, Elijovich notes. “If you could reduce the amount of salt that people eat, you will benefit the general population.”
Think beyond the shaker.
Salt and sodium are not exactly the same, but most of the sodium in processed and restaurant foods is salt, and the terms are used interchangeably.
A fast-food hamburger might have more than 1,000 milligrams of sodium; a large order of fries could add 400 mg. A can of chicken noodle soup might have more than 2,200 mg.
So how much sodium should you consume?
Federal dietary guidelines recommend adults eat no more than 2,300 mg of sodium a day. The American Heart Association says the ideal daily limit is 1,500 mg. Yet Americans eat an average of 3,400 mg of sodium a day.
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How to lower your sodium and salt intake
Read labels, Laffer says. And be aware that just because a product is labeled “low sodium” doesn’t mean it is.
Elijovich tells his patients to try cooking with flavorful spices, which can make them miss the taste of salt less. But he emphasizes that home cooking and a sprinkling of salt at dinner are not the main culprits.
“The majority of our salt intake is not in what we do,” he shares. “It’s in what we buy.”
Whatever you do, it could make a difference. Last year, an analysis of 85 studies published in the journal Circulation showed any reduction in sodium decreases blood pressure.
Anyone with high blood pressure needs to pay extra attention to salt. But everyone should know what it does, Laffer shares. “That’s my message to everyone that comes to my clinic. Even if it’s a young fit person who’s not overweight, I tell them – even for you, it’s worth being careful with salt.”
By The American Heart Association