While sodium is an essential nutrient, most people consume too much and are not even aware they are doing so. The body needs a small amount of sodium to work properly, but in excess it can increase a person’s risk for developing high blood pressure, which can lead to heart disease and stroke. That is why it is important to understand where most salt intake comes from and how to lower it.
The AMA’s What Doctors Wish Patients Knew™ series gives physicians a platform to share what they want patients to understand about today’s health care headlines and how to take charge of their health through preventive care.
For this installment, two AMA members shared what doctors wish patients knew about sodium consumption. They are:
- Brent M. Egan, MD, an internist in Greenville, South Carolina, and vice president of cardiovascular health at the AMA.
- Andrew M. Morton, MD, a family physician in Corydon, Indiana, at Baptist Health Medical Group.
Baptist Health Medical Group is part of the AMA Health System Member Program, which provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.
Americans consume too much salt
“The average American consumes about 3,400 milligrams of sodium a day, which is a lot,” said Dr. Morton. “This is compared to the recommended amount of 2,300 milligrams.”
What is alarming is that “many may not realize they consume too much sodium,” Dr. Egan said. “It would take us about a little over 1,000 milligrams a day to get from where we are to where the recommendation would be for the upper limit.
“And if we did that, we’d probably see a significant reduction in blood pressure, heart attack and stroke,” he added.
There’s a recommended limit
For people who “are interested in trying to minimize chronic disease,” their sodium intake should be about “2,300 milligrams a day,” said Dr. Egan. “What we do recommend though—for higher risk individuals—is to limit that to 1,500 milligrams of sodium a day.”
“If someone has high blood pressure, heart disease, that type of thing, 1,500 milligrams is probably a better target, but for the general population that’s really interested in limiting the burden of chronic disease, 2,300 milligrams is generally what is recommended,” he emphasized.
It’s hard to keep track of intake
“It’s tricky because sodium is everywhere, especially in processed things such as deli meats, breads, frozen meals, snack foods and anything canned,” said Dr. Morton. “Fast food and restaurant food also have a lot of sodium.”
“Sodium is hidden everywhere, especially in American diets because everything we eat is processed and that’s how the food is preserved through processing—with added sodium,” he said, emphasizing it can be “really hard to avoid.”
Certain people are affected more
Some populations are more at risk from high sodium intake than others such as “older adults and people with hypertension, diabetes and kidney disease,” said Dr. Morton, noting these people are higher risk and are more sensitive to the effects of the sodium and are more likely to have problems with it.”
Additionally, “you’d be surprised how expensive fresh food, fresh fruit is if you don’t grow it yourself,” he said. “So, for those who are from under-resourced or low-income areas, what is often readily available and affordable is processed food and, of course, that’s loaded with sodium.”
Sodium increases blood pressure
“With about half of the people with high blood pressure, increasing the sodium intake significantly raises blood pressure,” said Dr. Egan. “And for people without high blood pressure, about one in four will have a significant increase in blood pressure when they go from a sort of normal or low sodium diet to a higher sodium diet.
“There's also data to suggest that if our blood pressure is sensitive to salt, that further increases our risk for heart attack and stroke,” he added, noting “there may be some effects beyond the blood pressure alone such as oxidative stress.”
To explain why sodium increases blood pressure, Dr. Morton noted that “water follows sodium. So, if you have excess sodium in your diet, then that causes your body to retain water. Then that extra fluid increases the volume of your blood.
“This puts more pressure on your blood vessels, which can increase your blood pressure and can also cause edema or swelling in your legs,” he added.
Processed foods are high in sodium
“A lot of the snacks we like—any processed meats, lunch meats—and shellfish, are high in salt,” said Dr. Egan, adding that “fast food is common for a lot of folks and is high in sodium as well.”
“A general principle is if you can eat foods that are less processed—fruits, vegetables, whole grains, most meat—it is better for you,” he said. “If it hasn’t had salt added to it, it leaves people with a lot of good choices. But it doesn’t leave a lot of snack foods and fast foods, unfortunately.”
Potassium offers protection
Another issue, less often understood by patients, is that “processed foods are lower in potassium,” said Dr. Egan, adding that “potassium actually helps protect us against some of the bad effects of sodium.”
“When we eat unhealthy foods, not only are we getting more sodium, but typically we're getting less potassium,” he said. “So, lower potassium with high sodium consumption increases health risk beyond sodium content alone.”
That is why it is important to choose natural foods.
“Fruit and vegetables tend to have significantly more potassium than sodium,” said Dr. Egan. “But when we process those items, we typically add sodium and we may lose some potassium, unfortunately.”
Certain breads can have high sodium
Some of the different breads bought in the grocery store can have more sodium added than others, said Dr. Egan. That means, “if folks are getting quite a bit of bread, they can get a fair amount of sodium that way.
That is why “it’s just good to take a look at the nutrient label for how much sodium is in your bread,” said Dr. Egan. “But remember, whole grains are low in sodium.”
Shellfish are high in sodium
“It’s not all seafood, but shellfish in particular can be pretty high in sodium,” said Dr. Egan, noting that shellfish have about “five to eight times more sodium than other meats of similar calorie content.”
For example, while shrimp contain high levels of protein, their saltwater habitat can contribute to high sodium levels. Fresh-caught shrimp are also soaked in a salty brine to reduce their temperature and prevent ice crystals from forming during the freezing process, which adds to the sodium levels.
“Watch those food labels because we sometimes are surprised that things that we didn’t think tasted salty can have a lot of sodium in them,” said Dr. Egan.
Rinse sodium-containing canned foods
For canned foods, some people turn to sodium rinse. This means rinsing off sodium-containing canned foods such as beans, tuna and vegetables before eating.
“Not only are you getting rid of that fluid that they were in—which was high in sodium—but you do get rid of some of the sodium as well,” said Dr. Egan. “Now, if you could select fresh or frozen, that would be preferable.
“But sometimes—because fresh may be more expensive—folks may go with a canned option,” he added, noting that “rinsing those will reduce the amount of sodium that we take in.”
Try to cook at home more
When a person cooks their meals at home, it can help reduce sodium intake “because then we have control over how much sodium goes in,” said Dr. Egan, noting that “for people who are accustomed to eating quite a bit of salt, the food initially will taste very bland, almost like they’re chewing on cardboard or something.
“But interestingly, the taste buds adapt pretty well, so if they’re willing to put up with that for a few days, the taste buds readjust,” he added. “And in a few days, they’re appreciating flavors in food that they hadn’t recognized before because the sodium was actually dulling or numbing the taste buds so that they really didn’t taste some of the wonderful flavors that are in food.”
Sodium affects the immune system
“Many of our cells in the body—including our immune system—have sodium channels,” said Dr. Egan. “When we eat more salt, more of that sodium gets inside our cells and it even affects our immune system.
“A lot of folks are just not aware of that,” he added. “It's been suggested that some of those immune effects may in fact contribute to the elevation to high blood pressure, heart disease and stroke.”
You can get by with little sodium
“Obviously we need some sodium—it's essential for life,” said Dr. Egan. But there are some people who can “get by on about bout 250 milligrams of sodium and here we are with an average intake of 3,400 milligrams.”
“Now the body has to make a lot of adjustments, but we can get by with very little sodium,” he said, noting “there's very little danger in this country that most people won't get enough sodium, even if they're eating those fresh foods and not processed foods.
“They'll still—for the most part—get more than sufficient sodium that the body needs,” said Dr. Egan. “We live in a state of pretty much constant excess.”
What doctors wish patients knew
Subscribe for the answers to the latest questions patients are bringing to the exam room.
Blood pressure medicine is affected
“Some people may not be aware that when they eat more sodium, a lot of their blood pressure medications don't work as well,” said Dr. Egan, emphasizing that “several blood pressure medications work better when we have less salt in the diet.
“So even though they're taking blood pressure medications, they may not work as well and a lot of folks would like to not take more medications,” he added. “One way to help not require more medications is to reduce the sodium in the diet so the medications they're on work better.”
Salt can increase protein in the urine
“A high salt diet can also increase protein in the urine,” said Dr. Egan. Similarly, “some of the medications that we give for blood pressure reduce protein in the urine too.”
These medications “also don't work as well in reducing that protein unless we restrict our salt,” he said. “That is something that folks may not be aware of because certainly people with diabetes and kidney disease a lot of times have extra protein in the urine and high salt drives that.
“And even the medication we use to reduce it doesn’t work as well when there's extra salt in the diet,” Dr. Egan added.
Less sodium means health improvements
“Because sodium and blood pressure are so interlinked, reducing your sodium will definitely help reduce your blood pressure,” Dr. Morton said, “which then helps your heart and your kidneys.”
“One of the first recommendations for people with high blood pressure or marginal blood pressure is to get your sodium intake under control,” he emphasized.
Pay attention to the food label
“Soy sauce and a lot of the ketchups that we use have higher levels of sodium,” said Dr. Egan. “Tomato-based products also have quite a bit of sodium added as well.”
That is why “it’s always good to read food labels and to aim to get no more than 2,300 milligrams of sodium a day,” he said. “And, quite honestly, it’s probably important to shoot for lower than that because we’re going to get sodium that we didn’t read on the label in some way.”
“The thing we need to watch for is sometimes it looks like a one serving package, but it may be two or four servings,” said Dr. Egan. “And so, then we need to multiply that sodium by the number of servings.”
Focus on fresh food
For anyone who is trying to reduce their sodium intake without sacrificing flavor, Dr. Morton said “the biggest thing you can do is focus on fresh food. So, fresh fruits and vegetables, lean meats, no processed foods and whole grains. Those are the hallmarks for that.”
“Other things you could use instead of salt is herbs, spices and citrus vinegar, for example. So, there are a lot of other options,” he said. “If you’re in a position where that’s not really feasible, you can look for the low sodium options.”
Restaurants heavily season foods
While some restaurants list nutritional information, it is important to be mindful of what you’re ordering.
“I’d be fairly comfortable that most salads don’t have much sodium added, but the salad dressing that is put on there could be relatively high,” said Dr. Egan. “But it its vinegar and oil, you can be confident there’s probably not a lot of sodium added to the dressing.”
“If you know where you’re going, a lot of times you can find more detail by checking the menu before you go in,” he said. “Some restaurants will have those items that are designated healthier and have an American Heart Association label next to it. Those have been intentionally prepared to fit nutritional guidelines.
“So, if there are healthy options on the menu, sometimes those are flagged or noted and it makes it a little easier to choose those healthy foods,” Dr. Egan added.
There’s more you can do
“Sodium consumption is just part of the bigger picture when you’re looking at health,” Dr. Morton said, noting “sodium by itself isn’t going to do it. You also need exercise and to watch your diet.”
“Increase your activity and watching that diet—sticking to the fresh fruits and vegetables, whole grains—are going to help you in the long run across the board,” he said. “It’s about living a healthier lifestyle beyond reducing sodium intake.”
