Salt, Sodium, and Your Blood Pressure: Expert Insights

Salt plays an important role in our health, both good and bad. Like everything, it should be consumed in moderation.

Salt is essential to maintaining a healthy body, and sodium—the major component of salt—contributes to maintaining a balance of bodily fluids and keeps muscles and nerves operating properly.

Salt vs. Sodium

While the words salt and sodium are often used interchangeably by consumers, in the medical field they are different.

“Salt is what you find in the shaker on the dinner table. It is made from sodium chloride - 40% sodium and 60% chloride. Sodium is a mineral that is essential to optimal health that is found in packaged and prepared foods. It also occurs naturally in foods such as celery, beets, meats, shellfish, and milk,” said Dr. Quinn Pack, preventive cardiologist at Baystate Health.

How Salt and Sodium Impact Your Health

Too much salt disrupts the natural sodium balance in the body resulting in the body holding onto water - think your feet being swollen or your rings difficult to put on your fingers. And the extra water in your blood increases the pressure exerted by the blood against blood vessel walls, resulting in high blood pressure.

According to the US Food and Drug Administration, Americans eat on average about 3,400 mg of sodium per day – or about 150% of recommended levels. However, the Dietary Guidelines for Americans recommend adults limit sodium intake to less than 2,300 mg per day - equal to about 1 teaspoon of table salt. For children under age 14, recommended limits are even lower. And for those with high blood pressure, 1,500 to 2,000 mg per day is recommended.

Dr. Pack said when he asks patients if they eat a lot of salt, they often tell him, “Oh, I don’t eat any salt, I never use the salt shaker.”

“This is a really important point. Most of the salt Americans eat comes from sodium added to prepackaged foods by the manufacturer. Some 80% of the salt we eat is added at the time of processing. Table salt is only 5-10% of our intake, another 10% is naturally occurring and all else is added during food processing,” he said.

Salt and Sodium Impact Blood Pressure

In 1904, French doctors reported that six of their subjects who had high blood pressure were “salt fiends.” Over 100 years later, research continues to show a direct relationship between high sodium intake and high blood pressure. High salt intake puts you at risk for heart disease and stroke, the leading causes of death in the United States.

The good news is that a more recent study supports the American Heart Association’s position on salt and blood pressure. The authors noted two important facts - 1) consuming excess sodium beyond recommended levels is associated with high blood pressure and 2) reducing salt can be as effective as taking blood pressure medication.

The randomized trial compared the effects of high-sodium and low-sodium diets on blood pressure in adults with normal blood pressure and high blood pressure. It found that following a low-sodium diet significantly lowered blood pressure safely and rapidly in 70%-75% of participants in as little as one week, including people currently taking blood pressure medications.

“There are some studied populations in the world that do not have high blood pressure. These include populations where access to salt is very limited, and the preferred diet is high in fruits and vegetables. But while some salt is important for your diet, we know that excess salt is required for the development of high blood pressure. This naturally happens in America and in Western societies where diets are high in salt, and almost everyone gets high blood pressure eventually,” said Dr. Pack.

“Some Americans are more affected by salt than the average person, a condition known as salt sensitivity. Salt sensitive individuals include older people, the Black community, and those with kidney disease or diabetes. People who are salt sensitive are less efficient in eliminating excess salt from the body,” Dr. Pack said.

For salt sensitive individuals, eliminating excess salt has a more powerful effect on blood pressure reductions. Dietary salt reduction helps everyone with hypertension to lower blood pressure, but those with salt sensitivity benefit the most.

Foods High in Sodium

The first step in reducing your salt and sodium intake is being able to recognize high sodium foods. Some will surprise you!

“Canned soup is filled with enough salt to meet 100 percent of your daily allowance. Deli meats are loaded with salt. When you buy a frozen chicken breast, for example, most of the time, it was soaked in salt water before freezing. This makes the chicken breast weigh more and taste better. Because it retains water, it can also be sold for a higher price. Even frozen vegetables are sometimes soaked in salt water before freezing,” Dr. Pack said.

“Condiments are loaded with sodium. I call them the ‘five colors’ of salt - white for table salt, red for ketchup, yellow for mustard, green for pickles, and black for soy sauce. If you consider a standard hot dog, there is salt in the meat, in the bread, and then in the condiments. A single hot dog could get you 70% of your daily salt intake. The same goes for a burger at your favorite fast food restaurant. There is salt in the burger, in the bun, in the ketchup, in the pickles, in the special sauce. It can add up quickly, getting you 50 percent of your daily salt intake in just one sandwich,” he added.

According to the CDC, the following foods contain up to 40% of American sodium intake:

• bread
• deli meats
• pizza
• chicken dishes
• soup
• packaged cereals
• frozen waffles
• sandwiches and burgers
• cheese
• eggs with added ingredients when you scramble them or make an omelet
• burritos and tacos
• snack foods like pretzels, chips and popcorn

Other high sodium foods include:

• smoked or cured meats
• salted nuts
• canned vegetables which should be rinsed before heating
• salad dressing
• tomato paste
• jarred sauces
• soda
• energy drinks
• hot cocoa
• canned fruits
• stuffing and cranberry sauce
• stews
• spices such as onion and garlic salt and many others
• sauerkraut

Your favorite restaurant, whether ordering fast food or an expensive high-end meal, may be serving up more than just a delicious, flavor-filled meal.

“When at a fast-food restaurant, you are most likely getting 100% of your daily sodium, while a fancier restaurant could be as much as 150% and a buffet a whopping 200% depending on your choices,” Dr. Pack said.

How to Reduce Salt and Sodium Intake

Reducing salt in your diet isn’t easy, but it is achievable with planning.

“The first two to three weeks of reducing salt in your diet may make your food taste bland, but if you stick with it, the food will begin to taste better. It is a natural adaptation of the body with time. When you do this, you can use half as much salt as the recipe calls for in the kitchen, and you won’t taste any difference,” Dr. Pack said.

To help you select lower sodium foods, the U.S. Department of Health and Human Services offers a Lower Sodium Foods Shopping List to help guide you when you go to the grocery store.

When shopping be mindful of looking for foods labeled “low sodium” or “no salt added” and remember to use the Nutrition Facts label to check the amount of sodium to help you to choose products with 5% Daily Value (DV) or less. A food item with 20% DV or more of sodium is too high.

Lifestyle Changes for Blood Pressure Management

But using that salt shaker or consuming high-sodium foods are not the only risk factors for raising your blood pressure. Some risk factors can be changed simply by leading a healthier lifestyle, while factors that cannot be changed include age, sex, family history, genetics, race, ethnicity, and co-existing diseases such as diabetes and kidney disease

A heart healthy lifestyle can help prevent high blood pressure and its complications. The National Heart, Lung, and Blood Institute and Dr. Pack recommend:

• Choose heart-healthy foods that are lower in salt (sodium) and are rich in potassium. Fruits and vegetables are high in potassium. For more ways to limit your sodium, visit the DASH Eating Plan page or print out the Tips to Reduce Salt and Sodium handout.
• Avoid or limit alcohol. If you stop drinking alcohol, your systolic pressure will drop by 5 mm Hg systolic.
• Get regular physical activity. Even modest amounts can make a difference. Reducing the amount of time you sit each day can help lower your blood pressure by 4-5 mm Hg systolic.
• Aim for a healthy weight. For every five pounds you lose if overweight, your blood pressure will drop by 3-5 mm Hg systolic.
• Quit smoking 
• Control your cholesterol and blood sugar levels. To learn some tips to help manage your cholesterol level, read the booklet Therapeutic Lifestyle Changes to Lower Cholesterol
• Manage stress.
• Get enough good-quality sleep.

How to Mitigate Salt Intake

Did you indulge at a family BBQ or an unexpected fast food stop on a road trip?

“Research suggests that by following a high-potassium diet for a couple of days after a high-sodium meal you can reduce your blood pressure. Potassium works the opposite of sodium by helping to relax your blood vessels. Potassium with plenty of water helps to flush out excess sodium in your body through your kidneys. Unfortunately, most Americans get twice as much salt as needed and half as much potassium needed by the body,” said Dr. Pack, noting that following a DASH (Dietary Approaches to Stop Hypertension” diet can help.

Research supported by the National Heart, Lung, and Blood Institute (NHLBI) showed that blood pressure is reduced with an eating plan that is low in saturated fat, cholesterol, and total fat and that emphasizes fruits, vegetables, and fat-free or low-fat milk and milk products. Known as the DASH eating plan, it also includes whole grain products, fish, poultry, and nuts. It is reduced in lean red meat, sweets, added sugars, and sugar-containing beverages compared to the typical American diet. It is rich in potassium, magnesium, and calcium, as well as protein and fiber.

“The DASH diet—which is low in salt and includes plenty of fresh fruits, vegetables and other healthy foods—can lead to a 10 to 12 ml reduction in blood pressure which is equal to a maximum dose of blood pressure medication,” Dr. Pack said.

Foods that are high in potassium include:

• Bananas
• sweet potatoes
• apricots
• avocados
• beets
• cantaloupe and honeydew melons
• coconut water
• fat-free or low-fat milk
• fat-free and no sugar added yogurt
• grapefruits (for those not on a cholesterol-lowering medication)
• halibut
• leafy greens
• lima beans
• molasses
• mushrooms
• peas
• potatoes
• raisins and dates
• salmon
• spinach
• nuts and seeds
• oranges and 100% orange juice
• prunes and 100% prune juice
• tuna
• tomatoes and 100% tomato juice and tomato sauce
• whole grains

How to Control Blood Pressure

Doctors for years have been stressing the importance of knowing your numbers for many reasons.

“We refer to high blood pressure as the silent killer. Half of Americans have high blood pressure but are not aware of it. This is because high blood pressure rarely causes symptoms until they become serious such as kidney failure, heart failure, blindness, stroke and heart attack. Regular appointments with your physician are important when your blood pressure is checked as part of your physical health,” Dr. Pack said.

“Blood pressure gets worse if ignored and damages arteries resulting in high blood pressure. The longer you wait to control your high blood pressure, that harder it is to get it back under control,” he added. “There are plenty of good medications that exist that are well tolerated. There are more than 80 FDA approved medications. If you work with your doctors, they can handle just about any situation to get your blood pressure controlled,” he said.

However, many who are successful at leading a healthy lifestyle may still need one of two medicines, noted Dr Pack. Most people need two medications to control their blood pressure. This is because each medication only lowers blood pressure by 10 mm Hg or so, and most people need 20-30 mm Hg systolic of lowering by the time they get started on medications.

Among the many medications your doctor may prescribe could include ACE inhibitors, which relax blood vessels and prevent kidney damage; Angiotensin-2 receptor blocks, which also help to relax your blood vessels, calcium channel blockers, which also help relax your blood vessels, and diuretics which flush sodium and water out from your body in order to lower your blood pressure.

Research suggests that owning a home blood pressure monitor may help some people control high blood pressure.

Along with the American Heart Association and the American College of Cardiology, Dr. Pack recommends owning a home blood pressure monitor, especially for patients with high blood pressure. However, according to the CDC, only about a third of people with high blood pressure check it at home once a month.

“A home blood pressure monitor can offer you direct insight into your health. For many people, it provides an incentive to control their salt intake, especially if they see an increase in blood pressure after a salty meal. For your doctor, sharing your numbers will help to identify if your medications are working,” Dr. Pack said.

Even if you don’t have high blood pressure, a home unit can have other benefits.

“Patients often tell us their blood pressure is high because they are nervous. We call that white coat hypertension. It may or may not be accurate of your true blood pressure, so it needs additional investigation. Monitoring it at home for several days can help us determine if you really do have high blood pressure and, if needed, set a course of action to help bring it down,” Dr. Pack said.

To learn more about blood pressure monitors and how to use them, Consumer Reports has a Blood Pressure Monitor Buying Guide to help you choose.

“Blood pressure is the single most controllable disease in America. When trying to reduce your salt intake choose fresh or homemade over processed or prepared foods, follow a healthy lifestyle, and take your medications as directed by your doctor,” Dr. Pack said.