It occurs naturally in many foods, is added to others during the manufacturing process and is used as a flavoring agent at home and restaurants.
For some time, sodium has been linked to high blood pressure, which causes damage to your blood vessels and arteries when chronically elevated. In turn, this increases your risk of heart disease, stroke, heart failure and kidney disease.
Therefore, several health authorities have established guidelines for limiting sodium intake.
However, these guidelines have been controversial, as not everyone may benefit from a reduced-sodium diet.
This article explains the importance of sodium, potential risks of over- or underconsumption and how much sodium you should eat per day.
Necessary for Health
Despite its continued vilification, sodium is a necessary nutrient for good health.
It’s one of your body’s electrolytes, which are minerals that create electrically charged ions.
A major source of sodium in most diets is added salt in the form of sodium chloride — which is 40% sodium and 60% chloride by weight (1).
Because salt is widely used in food processing and manufacturing, processed foods account for an estimated 75% of total sodium consumed (1).
Most of your body’s sodium resides in your blood and the fluid surrounding your cells, where it helps keep these fluids in balance.
Along with maintaining normal fluid balance, sodium plays a key role in normal nerve and muscle function.
Your kidneys help regulate your body’s sodium levels by adjusting the amount that is excreted in your urine. You also lose sodium through sweating.
Dietary sodium deficiencies are very rare under normal conditions — even with very-low-sodium diets (2, 3).
Sodium is an important nutrient for health. It plays a vital role in nerve and muscle function and helps your body maintain normal fluid balance.
Linked to High Blood Pressure
It’s long been known that sodium increases blood pressure — particularly in people with elevated levels.
Most experts believe that the link between sodium and high blood pressure was first identified in France in 1904 (4).
Yet, it wasn’t until the late 1940s that this connection became widely recognized when the scientist Walter Kempner demonstrated that a low-salt rice diet could lower blood pressure in 500 people with elevated levels (5).
Since then, research has established a strong relationship between excessive sodium intake and high blood pressure (6, 7, 8, 9).
One of the largest studies on this topic is the Prospective Urban Rural Epidemiology trial, or PURE (10).
Analyzing the urine sodium levels of more than 100,000 people from 18 countries across five continents, researchers found that those who consumed more sodium had significantly higher blood pressure than those with lower intakes (10).
Using the same population, other scientists demonstrated that people who consumed more than 7 grams of sodium per day were at a higher risk of heart disease and early death than people who consumed 3–6 grams daily (11).
However, not everyone responds to sodium in the same way.
People with high blood pressure, diabetes and chronic kidney disease, as well as older adults and African Americans, tend to be more sensitive to the blood-pressure-raising effects of sodium (12, 13).
If you’re sensitive to salt, limiting sodium intake is recommended — as you may be at a higher risk of blood-pressure-related heart disease (14).
Sodium increases blood pressure. This effect is stronger in certain populations, making them more sensitive to salt and more prone to blood-pressure-related heart disease.
Official Dietary Recommendations
For decades, health authorities have urged people to limit their sodium intake to control blood pressure.
It’s estimated that your body only needs 186 mg of sodium per day to function properly.
However, it would almost be impossible to consume this little, still meet your energy needs and get the recommended intake of other important nutrients.
Therefore, the Institute of Medicine (IOM) recommends that healthy adults consume 1,500 mg (1.5 grams) of sodium per day (14).
At the same time, the IOM, USDA and the US Department of Health and Human Services recommend that healthy adults limit their daily sodium intake to less than 2,300 mg (2.3 grams) — the equivalence of one teaspoon of salt (14, 15).
This limit was established based on evidence from clinical studies that sodium intakes above 2,300 mg (2.3 grams) per day can adversely affect blood pressure and increase heart disease risk.
Due to the increased sodium loss through sweat, these guidelines don’t apply to highly active people like competitive athletes or workers who are exposed to heat.
Other organizations make different recommendations.
The WHO suggests consuming 2,000 mg (2 grams) of sodium per day, and the American Heart Association advises a much lower intake of 1,500 mg (1.5 grams) per day (16, 17).
Today, Americans consume much more sodium than health authorities recommend — averaging about 3,400 mg (3.4 grams) daily (15).
However, these recommendations have been controversial, as people with normal blood pressure levels may not benefit from restricting their sodium intake (18, 19).
In fact, evidence to suggest that consuming less salt decreases heart disease risk in healthy people is limited. It may even be harmful (18).
Health authorities recommend between 1,500 mg (1.5 grams) and 2,300 mg (2.3 grams) of sodium per day for heart health — much less than Americans consume on average.
Dangers of Underconsumption
Some evidence suggests that reducing sodium intakes to the recommended levels may be harmful.
In a review study comprising more than 133,000 people with and without high blood pressure from 49 countries across six continents, researchers examined how sodium intake affected the risk of heart disease and early death (20).
The review showed that — regardless of blood pressure — people who consumed less than 3,000 mg (3 grams) of sodium per day were more likely to have heart disease or die compared to people who consumed 4,000–5,000 mg (4–5 grams).
What’s more, those who consumed less than 3,000 mg (3 grams) of sodium per day had worse health outcomes than people consuming 7,000 mg (7 grams).
Still, researchers also found that people with high blood pressure who consumed more than 7 grams of sodium per day had a significantly greater risk of heart disease or death than people who consumed 4–5 grams.
These and other results suggest that too little sodium may be more detrimental to people’s health than higher intakes (10, 11, 20).
In both people with high and normal blood pressure, consuming too little sodium has been shown to worsen health more than consuming too much.
Should You Limit Your Intake?
People with high blood pressure who consume more than 7 grams of sodium per day should certainly consume less.
The same may apply if you have been instructed by your physician or registered dietitian to limit your sodium intake for medical reasons — as in the case of a low-sodium therapeutic diet.
However, cutting back on sodium doesn’t seem to make much of a difference for healthy people.
Though health authorities continue to push for lower sodium intakes, reducing sodium too much — below 3 grams per day — may negatively impact health.
Studies show that people who consume less than 3 grams of sodium per day are at a greater risk of heart disease and early death than people with an intake of 4–5 grams.
This raises concerns as to whether the current sodium guidelines — ranging from 1,500 mg (1.5 grams) to 2,300 mg (2.3 grams) — are doing more harm than good, as a growing body of evidence suggests that these levels may be too low.
That said, with only 22% of the population from 49 countries consuming more than 6 grams of sodium per day, the amount of sodium that healthy people are currently ingesting is probably safe (20).
If you consume more than 7 grams of sodium per day and have high blood pressure, it’s a good idea to limit your sodium intake. But if you’re healthy, the amount of salt you’re currently consuming is probably safe.
Other Ways to Control Your Blood Pressure and Improve Health
Achieving the low amounts of sodium that health authorities recommend can be difficult and may not be best for your health.
There are more practical and effective ways to control your blood pressure and improve your health without having to focus solely on how much sodium you consume.
Exercise is associated with a myriad of health benefits — including lower blood pressure (21).
A combination of aerobic and resistance training is ideal, but even just walking can help bring your levels down (22, 23, 24, 25).
If you’re unable to make it to a gym, try walking for at least 30 minutes per day. If this duration is too much to achieve at once, break it into three 10-minute blocks.
Eat More Fruits and Vegetables
Most people don’t eat enough fruits and vegetables.
These foods contain important nutrients — like potassium and magnesium — that may lower blood pressure (26, 27).
Vegetables like lettuce, beetroot, spinach and arugula are also good sources of nitrate, which increases your production of nitric oxide (28, 29).
Nitric oxide relaxes your blood vessels and arteries, causing them to dilate and increase blood flow — ultimately lowering your blood pressure (30).
Eat Fewer Calories
Sodium consumption is associated with calorie intake — the more calories you eat, the more sodium you consume (31).
SInce most people consume more calories than they need each day, simply cutting back on calories is the easiest way to reduce your sodium intake without much thought.
Eating fewer calories may also promote weight loss, which may lower your blood pressure as well (26, 32, 33, 34).
In addition to several other health consequences, heavy alcohol intake is significantly associated with elevated blood pressure (26, 35, 36, 37).
Women and men should limit their alcohol intake to one or two drinks per day, respectively. If you exceed these recommendations, you may want to cut back (38).
12 ounces (355 ml) of regular beer
8–9 ounces (237–266 ml) of malt liquor
5 ounces (148 ml) of wine
1.5 ounces (44 ml) of distilled spirits