Many tasty snacks contain salt to boost their flavour.
Is salt healthy or not ?
Health organizations have been warning us about the dangers of salt for a long time.
That’s because high salt intake has been claimed to cause a number of health problems, including high blood pressure and heart disease.
However, decades of research have failed to provide convincing evidence to support this (Report of the Dietary Guidelines for Americans Committee).
What’s more, many studies actually show that eating too little salt can be harmful.
This article takes a detailed look at salt and its health effects.
What Is Salt?
Salt is also called sodium chloride (NaCl). It consists of 40% sodium and 60% chloride, by weight.
Salt is by far the biggest dietary source of sodium, and the words “salt” and “sodium” are often used interchangeably.
Some varieties of salt may contain trace amounts of calcium, potassium, iron and zinc. Iodine is often added to table salt (Comparison of Salty Taste and Time Intensity of Sea and Land Salts from Around the World).
The essential minerals in salt act as important electrolytes in the body. They help with fluid balance, nerve transmission and muscle function.
Some amount of salt is naturally found in most foods. It’s also frequently added to foods in order to improve flavour.
Historically, salt was used to preserve food. High amounts can prevent growth of the bacteria that cause food to go bad.
Salt is harvested in two main ways: from salt mines and by evaporating sea water or other mineral-rich water.
There are actually many types of salt available. Common varieties include plain table salt, Himalayan pink salt and sea salt.
The different types of salt may vary in taste, texture and colour. In the picture above, the one on the left is more coarsely ground. The one on the right is finely ground table salt.
In case you’re wondering which type is the healthiest, the truth is that they are all quite similar.
Salt is mainly composed of two minerals, sodium and chloride, which have various functions in the body. It is found naturally in most foods, and is widely used to improve flavour.
How Does Salt Affect Heart Health?
Health authorities have been telling us to cut back on sodium for decades. They say you should consume no more than 2,300 mg of sodium per day, preferably less (WHO salt intake guidelines).
This amounts to about one teaspoon, or 6 grams of salt (it is 40% sodium, so multiply sodium grams by 2.5).
However, about 90% of US adults consume a lot more than that (Sodium and potassium intakes among US adults).
Eating too much salt is claimed to raise blood pressure, thereby increasing the risk of heart disease and stroke.
However, there are some serious doubts about the true benefits of sodium restriction.
It is true that reducing salt intake can lower blood pressure, especially in people with a medical condition called salt-sensitive hypertension (Salt Sensitivity of Blood Pressure in Humans).
But, for healthy individuals, the average reduction is very subtle.
One study from 2013 found that for individuals with normal blood pressure, restricting salt intake reduced systolic blood pressure by only 2.42 mm Hg and diastolic blood pressure by only 1.00 mm Hg (Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials).
That is like going from 130/75 mm Hg to 128/74 mm Hg. These are not exactly the impressive results you would hope to get from enduring a tasteless diet.
What’s more, some review studies have found no evidence that limiting salt intake will reduce the risk of heart attacks, strokes or death (Reduced dietary salt for the prevention of cardiovascular disease).
Low salt diets are very unpalatable and hard to stick to.
Limiting salt intake does result in a slight reduction in blood pressure. However, there is no strong evidence linking reduced intake to a lower risk of heart attacks, strokes or death.
Low Salt Intake Can Be Harmful
There is some evidence suggesting that a low-salt diet can be downright harmful.
The negative health effects include:
- Elevated LDL cholesterol and triglycerides: Salt restriction has been linked to elevated LDL (the “bad”) cholesterol and triglycerides (Effects of low sodium diet versus high sodium diet on blood pressure and lipids).
- Heart disease: Several studies report that less than 2,300 mg of sodium per day is linked to an increased risk of dying from heart disease (Sodium intake and mortality in the NHANES II follow-up study , The association between dietary sodium intake, ESRD, and all-cause mortality in patients with type 1 diabetes).
- Heart failure: One analysis found that restricting salt intake increased the risk of dying for people with heart failure. The effect was staggering, with a 160% higher risk of death in individuals who reduced their salt intake (Reduced dietary salt for the prevention of cardiovascular disease: a meta-analysis of randomized controlled trials (Cochrane review)).
- Insulin resistance: Some studies have reported that a low-salt diet may increase insulin resistance (Low-salt diet increases insulin resistance in healthy subjects, Moderate dietary salt restriction increases vascular and systemic insulin resistance).
- Type 2 diabetes: One study found that in type 2 diabetes patients, less sodium was associated with an increased risk of death (Dietary salt intake and mortality in patients with type 2 diabetes).
A low-salt diet has been linked to higher LDL and triglyceride levels, and increased insulin resistance. It may increase the risk of death from heart disease, heart failure and type 2 diabetes.
There Are Situations When Eating Salt is Beneficial
There are occasions when eating salty snacks is definitely a good idea.
For example in hot climates or when the weather is very hot. In hot weather we sweat a lot and lose salt and water. We are then at risk of dehydration and low blood pressure due to loss of fluid and salt. In extreme circumstances this can cause people to collapse. Eating salty snacks and also drinking plenty of plain water is a very good idea at these times.
When exercising hard for long periods of time, especially in hot weather, we lose salt and water as sweat. Therefore it is a good idea to snack on salty snacks and to consume plain water when exercising for a long time, particularly in hot conditions. This will improve your performance and prevent collapse from salt and water loss.
Which Foods Are High in Salt/Sodium?
Most of the salt in the modern diet comes from restaurant foods or packaged, processed foods.
In fact, it is estimated that about 75% of the salt in the US diet comes from processed food. Only 25% of the intake occurs naturally in foods or is added during cooking or at the table (Relative contributions of dietary sodium sources).
Salted snack foods, canned and instant soups, processed meat, pickled foods and soy sauce are examples of high-salt foods.
There are also some seemingly un-salty foods that actually contain surprisingly high amounts of salt, including bread, cottage cheese and some breakfast cereals.
If you are trying to cut back, then food labels almost always list the sodium content.
Foods that are high in salt include processed foods, such as salted snacks and instant soups. Less obvious foods, such as bread and cottage cheese, may also contain a lot.
Should You Eat Less Salt?
Some health conditions make it necessary to cut back on salt. If your doctor wants you to limit your intake, then definitely continue to do so.
However, if you are a healthy person who eats mostly whole, single ingredient foods, then there is probably no need for you to worry about your salt intake.
In this case, you can feel free to add salt during cooking or at the table in order to improve flavour.
Eating extremely high amounts of salt can be harmful, but eating too little may be just as bad for your health (Urinary sodium and potassium excretion and risk of cardiovascular events).
As is so often the case in nutrition, the optimal intake is somewhere between the two extremes.