Sodium is an important mineral that performs many essential functions in your body.
It’s found naturally in foods like eggs and vegetables and is also a main component of table salt (sodium chloride).
Though it’s vital to health, dietary sodium is sometimes limited under certain circumstances.
For example, a low-sodium diet is commonly prescribed to people with certain medical conditions, including heart failure, high blood pressure and kidney disease.
This article explains why a low-sodium diet is necessary for some people and reviews benefits, risks and foods to avoid and eat.
Sodium is an essential mineral involved in many important bodily functions, including cellular function, fluid regulation, electrolyte balance and maintaining blood pressure ().
Because this mineral is vital to life, your kidneys tightly regulate its levels based on the concentration (osmolarity) of bodily fluids ().
Sodium is found in most foods you eat — though whole foods like vegetables, fruits and poultry contain much lower amounts.
Plant-based foods like fresh produce generally have less sodium than animal-based foods, such as meat and dairy products.
Sodium is most concentrated in processed and packaged foods like chips, frozen dinners and fast food where salt is added during processing to enhance flavor.
Another major contributor to sodium intake is adding salt to food when preparing meals in your kitchen and as a seasoning before eating.
A low-sodium diet limits high-sodium foods and beverages.
Healthcare professions typically recommend these diets to treat conditions such as high blood pressure or heart disease.
Although there are variations, sodium intake is generally kept to less than 2–3 grams (2,000–3,000 mg) per day ().
For reference, one teaspoon of salt contains about 2,300 mg of sodium ().
When following a low-sodium diet, foods high in sodium must be limited or completely avoided to keep your sodium intake under the recommended level.
Summary Healthcare professionals recommend low-sodium diets to treat certain medical conditions. Sodium levels are typically restricted to less than 2–3 grams (2,000–3,000 mg) per day.
Low-sodium diets are some of the most commonly used diets in hospital settings.
This is because research shows that restricting sodium may help control or improve certain medical conditions.
Kidney disease, such as chronic kidney disease (CKD) or kidney failure, negatively impacts kidney function.
When your kidneys are compromised, they’re unable to effectively remove excess sodium or fluid from your body.
If sodium and fluid levels become too high, pressure builds in your blood, which can cause further damage to already compromised kidneys ().
For these reasons, The National Kidney Foundation recommends that all people with CKD restrict their sodium intake to less than 2 grams (2,000 mg) per day ().
A review of 11 studies in people with CKD found that moderate sodium restriction significantly reduced blood pressure and protein in the urine (a marker of kidney damage) ().
High Blood Pressure
High blood pressure is a risk factor for various conditions, including heart disease and stroke ().
A high-sodium diet has been linked to elevated blood pressure.
For example, a recent study in 766 people demonstrated that those with the highest urinary sodium excretion had the highest blood pressure levels ().
Many studies have shown that reducing salt intake may help decrease high blood pressure in people with elevated levels.
A review of six studies in more than 3,000 people showed that salt restriction lowered blood pressure in adults — with the strongest impact observed in those with high blood pressure ().
Salt-sensitivity of people with high blood pressure varies widely and certain subgroups — such as African Americans — tend to be more impacted by high-salt diets ().
Nevertheless, low-sodium diets are commonly prescribed as a natural treatment for all people with high blood pressure.
Low-sodium diets are commonly recommended to those with heart conditions, including heart failure.
When your heart is compromised, kidney function declines, which can lead to sodium and water retention ().
Eating too much salt could cause fluid overload in people with heart failure and lead to dangerous complications, such as shortness of breath.
Regulatory agencies recommend that people with mild heart failure limit their sodium intake to 3,000 mg per day while those with moderate to severe heart failure should reduce their intake no more than 2,000 mg daily (13).
However, while many studies have shown that low-sodium diets benefit those with heart failure, others have noted that non-restrictive diets lead to better outcomes.
For example, a study in 833 people with heart failure found that a sodium-restricted diet with less than 2,500 mg per day was associated with a significantly higher risk of death or hospitalization than unrestricted-sodium diets with 2,500 mg or more per day ().
Summary Low-sodium diets are commonly prescribed to people with kidney disease, heart disease or high blood pressure in order to manage symptoms and prevent complications.
Following a low-sodium diet may benefit health in several ways.
May Reduce Blood Pressure
As stated above, a low-sodium diet may help decrease blood pressure.
Studies have shown that transitioning to a low-sodium diet can lead to small yet significant changes in blood pressure, especially in people with elevated levels.
A review of 34 studies demonstrated that a modest reduction in salt intake for four or more weeks led to significant reductions in blood pressure in people with both high and normal levels ().
In the participants with high blood pressure, the average reduction in systolic and diastolic blood pressure was 5.39 mmHg and 2.82 mmHg, respectively.
By comparison, people with normal levels noticed a 2.42 mmHg reduction in systolic blood pressure (the top number of a reading) and 1.00 mmHg reduction in diastolic blood pressure (the bottom number of a reading) ().
May Help Decrease Cancer Risk
High-salt diets have been linked to certain types of cancers, including of the stomach.
A review of 76 studies in more than 6,300,000 people found that for every five-gram increase of dietary salt per day — from high-salt processed foods — the risk of stomach cancer increased by 12% ().
Research has shown that high-salt diets can damage the mucosal lining of your stomach and increase inflammation and the growth of H. Pylori bacteria — all of which may raise stomach cancer risk ().
On the other hand, a diet low in high-sodium processed foods and rich in fruits and vegetables is associated with a lower risk of stomach cancer ().
May Improve Diet Quality
Many unhealthy foods are extremely high in sodium.
Fast food, packaged items and frozen meals are not only loaded with salt but also tend to be high in unhealthy fats and calories.
Frequent consumption of these foods has been linked to health conditions such as obesity, diabetes and heart disease ().
On a low-sodium diet, these high-salt foods are off limits, which may improve your overall diet quality.
Summary Following a low-sodium diet may decrease blood pressure, lower your risk of stomach cancer and improve diet quality.
The following foods are high in sodium and should be avoided on a low-sodium diet:
- Fast food: Burgers, fries, chicken fingers, pizza, etc.
- Salty snack foods: Salted pretzels, chips, salted nuts, salted crackers, etc.
- Frozen dinners: Frozen meat dishes, frozen pizza, etc.
- Processed meats: Bacon, sausage, lunch meats and hot dogs.
- Salted, canned products: Vegetables, pastas, meats, fish, etc.
- Salty soups: Canned soups and packaged soups.
- Cheese and dairy: Cheese, cheese spreads, cottage cheese, buttermilk, salted butter and cheese sauce.
- High-sodium baked goods: Salted rolls, salted bagels, croutons and crackers.
- Baking mixes: High-sodium waffle, pancake or cake mixes.
- Boxed meals: Macaroni and cheese, pasta meals, rice meals, etc.
- High-sodium side dishes: Stuffing, boxed au gratin potatoes, hash browns and rice pilaf.
- Sauces and condiments: Gravy, soy sauce, commercial tomato sauce, salsa and salad dressing.
- Pickled vegetables: Pickles, olives and sauerkraut.
- Certain drinks: Regular vegetable juice, juice blends and salty alcoholic beverages.
- Seasonings: Salt and salt blends.
Though certain foods like vegetables and unprocessed meats naturally contain small amounts of sodium, it’s insignificant compared to the amount of sodium added to commercially prepared foods.
The best way to avoid high-sodium foods is to restrict salty snack foods, fast food and packaged meals.
Summary Processed meats, cheese, frozen meals, fast foods and salty condiments are just some of the foods that are highest in sodium and should be avoided on a low-sodium diet.
If you follow a low-sodium diet, it’s important to choose foods that are naturally low in sodium or contain limited amounts of added salt.
The following foods are low in sodium and safe to eat on a low-sodium diet:
- Fresh and frozen vegetables (without sauces): Greens, broccoli, cauliflower, peppers, etc.
- Fresh, frozen or dried fruits: Berries, apples, bananas, pears, etc.
- Grains and beans: Dried beans, brown rice, farro, quinoa and whole wheat pasta.
- Starchy vegetables: Potatoes, sweet potatoes, butternut squash and parsnips.
- Fresh or frozen meat and poultry: Chicken, turkey, beef or pork.
- Fresh or frozen fish: Cod, sea bass, tuna, etc.
- Eggs: Whole eggs and egg whites.
- Healthy fats: Olive oil, avocado and avocado oil.
- Low-sodium soups: Low-sodium canned or homemade soups.
- Dairy products: Milk, yogurt, unsalted butter and low-sodium cheeses.
- Bread and baked goods: Whole-wheat bread, low-sodium tortillas and unsalted crackers.
- Unsalted nuts and seeds: Pumpkin seeds, almonds, peanuts, etc.
- Low-sodium snack foods: Unsalted pretzels, unsalted popcorn and unsalted tortilla chips.
- Low-sodium condiments: Vinegar, mayonnaise, low-sodium salad dressing and low-sodium sauces.
- Low-sodium beverages: Tea, coffee, low-sodium vegetable juice and water.
- Low-sodium seasonings: Garlic powder, no-salt blends, herbs and spices.
Summary Foods like fresh vegetables, fruits, most dairy products, eggs and unsalted nuts are naturally low in sodium.
Major health organizations, such as The Centers for Disease Control and Prevention, recommend that adults consume no more than 2,300 mg of salt per day and higher-risk groups, such as African Americans and older adults, no more than 1,500 mg ().
It’s clear that a reduced-sodium diet may decrease blood pressure in those with elevated levels and that high-salt diets increase stomach cancer risk, but evidence of other benefits of reducing this important mineral is conflicting.
For example, though sodium restriction is commonly used to treat heart failure, some studies have shown that reducing sodium can have a negative impact on patient health.
A study in 833 people with heart failure demonstrated that restricting sodium to less than 2,500 mg per day was associated with a significantly higher risk of death or hospitalization, compared to a non-restricted-sodium diet ().
Other studies have shown similar results (, ).
What’s more, research has noted that consuming too little sodium can negatively impact heart health.
A review of 23 studies found that both high and low sodium intake was associated with a higher risk of all-cause mortality and heart disease events ().
Low sodium intake has also been linked to several other adverse health effects.
Consuming too little salt may lead to increased cholesterol and triglycerides, insulin resistance and hyponatremia (too little sodium in the blood) (, , ).
While avoiding high-sodium, unhealthy foods like fast food is always best for your health, it’s unnecessary for most healthy people to restrict sodium when following a balanced diet rich in whole foods.
Summary Restricting sodium too much may lead to elevated cholesterol levels, insulin resistance and hyponatremia. Some studies have shown that low-sodium diets negatively impact people with heart failure.
If you follow a low-sodium diet, seasoning foods and making meals palatable can be challenging.
However, there are many easy ways to make your food delicious while avoiding salt.
Here are some tips for food prep and cooking on a low-sodium diet:
- Use lemon juice as a salt substitute.
- Cook with fresh herbs rather than salt.
- Experiment with new spices.
- Use citrus juices and olive oil as a bright, zesty salad dressing.
- Snack on unsalted nuts sprinkled with a mix of herbs.
- Make homemade soup flavored with garlic and ginger.
- Use more fresh produce in your meals and snacks.
- Prepare homemade hummus using dried chickpeas and flavor it with garlic and herbs.
- Make a low-sodium marinade with olive oil, garlic, vinegar, honey and ginger.
Make More Meals at Home
According to research, foods eaten outside of the home are the leading contributor to sodium intake.
A study in 450 adults from different geographic areas found that commercial and restaurant foods eaten outside of the home accounted for 70.9% of total sodium intake ().
One of the best ways to reduce the amount of sodium in your diet is to control what goes into your food by cooking at home.
Eating more meals at home will not only reduce your sodium intake but can also help you lose weight.
A study in more than 11,000 adults found that those who cooked meals at home more frequently had lower body fat and better overall diet quality than people who ate fewer meals at home ().
Summary Using fresh herbs, spices and citrus to flavor food and cooking more meals at home are helpful tips if you’re following a low-sodium diet.
Low-sodium diets may improve high blood pressure, chronic kidney disease and overall diet quality. They may also decrease stomach cancer risk.
Yet, too little sodium may have negative health effects, and this type of diet is unnecessary for most people.
If you follow a low-sodium diet, choose fresh and avoid salty foods. Cooking more meals at home is another great way to control your salt intake, allowing you to stay within your physician’s recommendation.