The Health Risks of Too Much Salt
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Most Americans, including older adults, consume too much salt—or more accurately, sodium—than they should. In fact, a recent report from the Centers for Disease Control and Prevention found that those 51 and older average about 3,000 mg of sodium per day, twice what the American Heart Association recommends and about 30 percent more than the Department of Agriculture dietary guidelines of fewer than 2,300 mg per day.
Why should you care? Because a steady stream of studies over decades has also linked too much sodium in the diet to hypertension (high blood pressure) and other risk factors for heart disease.
“There’s consistent evidence that in countries with high levels of salt intake, blood pressure rises more steeply with the aging of the population,” says Dariush Mozaffarian, M.D., dean of the Friedman School of Nutrition Science and Policy at Tufts University. “And in countries with low salt intake, blood pressure rates do not rise as much with age.”
But you may also have heard conflicting advice about sodium and whether everyone really needs to reduce consumption. It’s true that certain studies have shown no decrease in deaths from cardiovascular disease in people who ate less sodium. And others have even suggested that low-sodium diets could have adverse health outcomes, such as a rise in overall cholesterol and triglyceride levels.
“Most of the latter studies showing negative effects have been done with very large, very rapid reductions in sodium,” Mozaffarian says. “With slow reductions over time, there is very little plausible evidence of harm.”
Sodium and Health
When you consume excess sodium on a regular basis, the kidneys can’t keep up with the need to excrete it. It gets stored in the blood, increasing water retention and blood volume. “The heart then has to work harder to pump the blood, which increases pressure on your arteries,” says Brigid Titgemeier, R.D.N., a nutritionist at the Cleveland Clinic Center for Functional Medicine. “Over time, the arteries stiffen, causing your blood pressure to go up.” Even if it doesn’t, some evidence suggests that high-sodium diets could interfere with the proper functioning of the endothelium (lining of the arteries), causing inflammation and stiffening.
Reducing sodium is especially important for people with hypertension. “A high sodium intake makes it harder to regulate your blood pressure even with medication,” says Lisa J. Harnack, Dr.P.H., R.D., a professor of epidemiology and community health at the University of Minnesota. But simply eating less salt could mean being able to control your blood pressure with a lower dose of drugs. Research has also shown a connection between high-sodium diets and other health problems, such as kidney stones and even stomach cancer.
Weight gain might be a consequence of a high-sodium diet, too. In a study published in The Journal of Clinical Investigation, two groups of Russian cosmonauts were sealed in mock spaceships for 105- and 205-day simulated flights to Mars. They had identical diets except for the amount of salt. Those consuming the most sodium were hungrier. It could be that excess sodium triggers appetite because the body has to work harder to eliminate it (and therefore requires more calories).
Sleuthing Out Sodium
A big part of reducing your sodium intake is realizing where it’s lurking. And it might surprise you to learn that your saltshaker is the least of your worries. According to a study published this year in the journal Circulation, a mere 5 percent of Americans’ sodium intake comes from salt added at the table, and only 6 percent comes from salt added during cooking. By contrast, 71 percent comes from the packaged and restaurant foods we eat. (Read "9 Foods That Are Surprisingly Salty" to discover those that are higher in sodium than you might think.)
According to the CDC report, the top 10 sodium-laden food categories are breads (such as rolls, bagels, and English muffins), pizza, sandwiches, cold cuts and cured meats, soups, burritos and tacos, savory snacks (including chips, popcorn, pretzels, and crackers), chicken, cheese, and eggs and omelets. These categories make up 44 percent of Americans’ overall sodium intake.
Sodium in our food supply is so pervasive that it’s present in almost every type of processed food you buy. “Sodium in processed foods serves multiple functions beyond adding salty taste,” Harnack says. “It’s part of the leavening process for yeast breads, it’s used to enhance the texture of baked goods and crispy snacks, and it’s used as a preservative in canned foods.”
Cut Your Sodium Intake
Anyone who has been diagnosed with high blood pressure is probably familiar with the DASH (Dietary Approaches to Stop Hypertension) diet. It involves reducing sodium and increasing calcium, magnesium, and potassium. That means plenty of fruits, vegetables, whole grains, and low-fat dairy, and less sodium, saturated fat, sugars, and processed foods. Over the past two decades, researchers have consistently found that following the DASH diet lowers blood pressure by as much as 12 points for systolic (the upper number) and 6 points for diastolic (the lower one).
But even if you’re not strictly adhering to the DASH diet, you should follow its basic tenets, which include eating more whole, unprocessed foods and upping your intake of fruits and vegetables. “The most important change you can make is to cook whole foods and eat at home,” Titgemeier says. “Eating out and relying on prepared, packaged, and frozen meals are big contributing factors to the rise in hypertension.”
When you cook, don’t automatically reach for the saltshaker. Instead, experiment with different herbs and spices that can add flavor without adding sodium. “Fresh herbs and garlic are flavorful, and many also have anti-inflammatory benefits,” Titgemeier says. Dried ones are also great salt replacements and have the added benefit of lasting longer than fresh. Titgemeier also recommends using vinegars and citrus for marinades and cooking. “They are acidic, which works as a natural flavor enhancer.”
Learning to love new flavors while weaning yourself off excess salt can add up to a significant reduction in your overall sodium intake.
And the best part? If you aim for a 10 to 15 percent reduction in the amount of sodium you eat, chances are you won’t be able to tell the difference. “Sodium receptors on the tongue recalibrate over time,” Mozaffarian says. “So if you reduce your intake gradually, you won’t even notice.” As an example, in a 2016 Australian study researchers replaced participants’ regular bread in a blind test with breads containing 12.5 or 25 percent less sodium. People liked the reduced-sodium versions just as much, and they didn’t even notice that one was significantly less salty than what they usually ate.
When buying packaged foods, compare brands. Once you find a lower-sodium version of a product you like, stick with it. You can cut the sodium in canned foods by rinsing canned beans, vegetables, and fish before eating them and by looking for cans (such as soup) labeled “low sodium.” According to the Food and Drug Administration, that means a product can’t have more than 140 mg of sodium per serving. Restaurant foods are often very high in sodium, so ask your server to point out low-sodium options on the menu or ask whether the chef can limit the salt in your dish.
Can You Get Too Little Sodium?
Though most of us are worried about getting too much sodium (and rightly so), it's possible to have too little of the mineral in your blood. The condition is called hyponatremia, and it can be life-threatening. Older adults are at higher risk of this complication because of certain medications (such as antidepressants, diuretics, and opioids) and medical conditions (congestive heart failure, kidney disease, and liver failure) that contribute to low sodium levels in the body. Overzealous water consumption could also cause the problem.
A study published in 2011 in the journal Therapeutic Advances in Drug Safety noted that 18 percent of nursing-home residents suffered from mild, chronic hyponatremia. “Older adults with hyponatremia may show signs of cognitive changes, lethargy, headache, and nausea,” says Paul Y. Takahashi, M.D., a geriatrician at the Mayo Clinic.
He recommends that you be checked for hyponatremia regularly if you're on any of the medications that put you at risk. “We also check older patients if they get pneumonia, a urinary tract infection, flu, or gastroenteritis, which puts them at risk of dehydration and thus hyponatremia,” Takahashi says.
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