For years, the thinking on salt has been that less is always better: Too much raises blood pressure, which can increase your risk of heart disease. So we all curbed our French fries addiction and laid off the salt shaker. But new research shows that the factors affecting blood pressure are much more complex.
The Current Recommendations on Sodium
The American Heart Association (AHA) recommends a maximum of 2,300 mg of sodium a day for most people — that’s about one teaspoon of salt — ideally 1,500 mg.
James R. Johnston, MD, Professor of Medicine at the University of Pittsburgh, explains that’s essentially a no-added-salt diet. “You’re not using the salt shaker for cooking or at the dinner table,” he says. “My patients say it’s like eating cardboard. We have a very highly developed taste for salt.”
Most of us get 50 percent more than the AHA’s recommendation — in large part due to packaged foods. A just-released study found that, on average, people eat 3,500 mg of sodium per day. Packaged and restaurant food is the leading source (70.9 percent). Conversely, salt added in home cooking (5.6 percent) and at the dinner table (4.9 percent) barely registered. These numbers led the U.S. Food and Drug Administration (FDA) to release voluntary guidelines last June, calling for food manufacturers to ease up on the salty stuff, too.
So How Low Should You Go?
But ever since we’ve demonized salt and limited it from our diets, a number of recent studies have questioned whether the current limit might be too low. A preliminary study found that people who consumed less than 2,500 mg of sodium actually had a higher risk of high blood pressure than those who got 3,500 mg. Another much larger review study published last year found that eating less than 3,000 mg of sodium per day was associated with an increased risk for high blood pressure, stroke and heart disease, as was eating more than 7,000 mg.
Because of this discrepancy, researchers are taking another look at sodium recommendations because the current ones don’t work for everyone, says Johnston. “What causes high blood pressure is very poorly understood. Some groups of people are much more sensitive to salt intake. A lot has to do with genetics,” he says. “We’re trying to find out the best value.”
This new research also points out that not getting enough potassium can increase your risk for high blood pressure and heart disease. Potassium helps your kidneys get rid of sodium, Johnston explains.
“The whole idea that sodium is acting alone in causing high blood pressure may be false,” says Johnston. “Maybe it’s not only sodium but potassium. The data before didn’t control closely enough for potassium. Now we’re looking at it closely again, but we’re not close to having it worked out.”
Potassium comes mostly from fruits and vegetables that most of us aren’t getting enough of. “If we got more fruits and veggies, it could help us better control blood pressure,” says Isabel Smith, R.D.
Why We Need Sodium
Before McDonald’s, Doritos and Hot Pockets, we had to seek out salt to live. “Sodium helps our bodies hold on to fluid so we’re not dehydrated. It helps muscles contract and keeps our nerves healthy. At less than 500 mg per day, you can’t survive,” says nutritionist Karen Ansel, R.D. She explains that sodium pulls water into your blood vessels — which is why too much can increase blood pressure.
And you will feel the effects if you’re not getting enough. Ansel says for years she experienced dizziness. She later found out it was due to very low sodium levels. “We see that with health-conscious people. I had to change the way I ate because of that,” Ansel says. “So we do need sodium. But most of us are eating too much.”
How Much Salt Should You Eat?
A person’s ideal sodium consumption depends on many factors. Some people are more sensitive: A level that raises one individual’s blood pressure might not affect another person’s at all, says Ansel. What’s more, people who exercise and sweat a lot need more sodium than those who are less active.
For most of us, experts say we should still aim for no more than 2,300 mg of salt per day. But that doesn’t necessarily mean skipping the shaker. “If you eat few processed and packaged foods, and you eat a lot of vegetables and fruits, which contain potassium, and exercise, most people don’t have to worry too much about too much salt,” says Smith. “I like people to focus on other healthy behaviors that naturally help keep blood pressure down.”
6 Expert Tips to Keep Your Sodium in Check
For now, experts agree on the following.
- Get your blood pressure checked. If it’s too high, cut down on salt and eat more fruits and veggies, says Johnston. Start slowly: “You can retrain your taste for salt, but if you abruptly go to a low- or no-sodium diet you’re going to be miserable,” he says.
- Skip processed foods. “Most of the salt we eat is not from cooking,” says Ansel. Cut out as many salty packaged foods like deli meats, hot dogs and ready-made pasta as possible.
- Cook when you can. Since restaurant foods are high in sodium, cooking meals with fresh ingredients makes a big difference in terms of your overall intake.
- Keep an eye on portions. Ansel points out that bread is actually the number one source of sodium in our diets — not because it’s super salty but because we simply eat so much of it. “If you’re having eight slices of bread or two big bagels a day, that’s too much,” she says.
- Sprinkle salt on top of, not in, foods. “Instead of using salt in dressings and sauces, I like people to use it on top of their food in small quantities. It feels more decadent and like they’re getting more than they actually are,” says Smith.
- Use whatever type you prefer. Ansel says there’s not really a difference nutritionally between table and sea salt. Table salt has added iodine, which helps your thyroid function (and you might need more if you don’t eat fish). “Sea salt does have more of a mix of minerals that can give different flavor to food,” Ansel adds.
The bottom line: More research needs to be done to revamp the recommendations. “We keep scratching the surface with science. The next thing we learn is always changing everything we think we know,” Johnston says.