The best of EcoWatch, right in your inbox. Sign up for our email newsletter!
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.
Photo credit: Shutterstock
However, decades of research have failed to provide convincing evidence to support this (1).
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 by far the biggest dietary source of sodium and the words “salt" and “sodium" are often used interchangeably.
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 flavor.
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.
This is What Salt Looks Like:
Photo credit: Shutterstock
The different types of salt may vary in taste, texture and color. In the picture above, the salt on the left is more coarsely ground. The salt 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.
Bottom Line: 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 flavor.
How Does Salt Affect Heart Health?
This amounts to about one teaspoon or 6 grams of salt (salt is 40 percent sodium, so multiply sodium grams by 2.5).
However, about 90 percent of U.S. adults consume a lot more than that (7).
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 (8).
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 mmHg and diastolic blood pressure by only 1.00 mmHg (9).
That is like going from 130/75 mmHg to 128/74 mmHg. These are not exactly the impressive results you would hope to get from enduring a tasteless diet.
Bottom Line: Limiting salt intake does result in a slight reduction in blood pressure. However, there is no strong evidence linking reduced salt 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 (12).
- Heart disease: Several studies report that less than 3,000 mg of sodium per day is linked to an increased risk of dying from heart disease (13, 14, 15, 16).
- 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 percent higher risk of death in individuals who reduced their salt intake (17).
- Insulin resistance: Some studies have reported that a low-salt diet may increase insulin resistance (18, 19, 20, 21).
- Type 2 diabetes: One study found that in type 2 diabetes patients, less sodium was associated with an increased risk of death (22).
Bottom Line: 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.
High Salt Intake is Linked to Stomach Cancer
Stomach cancer, also known as gastric cancer, is the fifth most common cancer.
It is the third leading cause of cancer death worldwide and is responsible for more than 700,000 deaths each year (23).
A massive review article from 2012 looked at data from seven prospective studies, including a total of 268,718 participants (28).
It found that people with high salt intake have a 68 percent higher risk of stomach cancer, compared to those who have a low salt intake.
Exactly how or why this happens is not well understood, but several theories exist:
- Growth of bacteria: High salt intake may increase the growth of Helicobacter pylori, a bacteria that can lead to inflammation and gastric ulcers. This may increase the risk of stomach cancer (29, 30, 31).
- Damage to stomach lining: A diet high in salt may damage and inflame the stomach lining, thus exposing it to carcinogens (25, 31).
However, keep in mind that these are observational studies. They can not prove that high salt intake causes stomach cancer, only that the two are strongly associated.
Bottom Line: Several observational studies have linked high salt intake with an increased risk of stomach cancer. This may be caused by several factors.
Which Foods are High in Salt/Sodium?
In fact, it is estimated that about 75 percent of the salt in the U.S. diet comes from processed food. Only 25 percent of the intake occurs naturally in foods or is added during cooking or at the table (32).
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.
Bottom Line: 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 of salt.
Should You Eat Less Salt?
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 flavor.
Eating extremely high amounts of salt can be harmful, but eating too little may be just as bad for your health (16).
As is so often the case in nutrition, the optimal intake is somewhere between the two extremes.
This article was reposted from our media associate Authority Nutrition.
YOU MIGHT ALSO LIKE
EcoWatch Daily Newsletter
By Pam Radtke Russell in New Orleans
Local TV weather forecasters have become foot soldiers in the war against climate misinformation. Over the past decade, a growing number of meteorologists and weathercasters have begun addressing the climate crisis either as part of their weather forecasts, or in separate, independent news reports to help their viewers understand what is happening and why it is important.
While airlines only serve bottled drinking water directly to customers, they use the plane's water for coffee and tea, and passengers can drink the tap water. Aitor Diago / Getty Images
You might want to think twice before washing your hands in an airplane bathroom.
By Allegra Kirkland, Jeremy Deaton, Molly Taft, Mina Lee and Josh Landis
Climate change is already here. It's not something that can simply be ignored by cable news or dismissed by sitting U.S. senators in a Twitter joke. Nor is it a fantastical scenario like The Day After Tomorrow or 2012 that starts with a single crack in the Arctic ice shelf or earthquake tearing through Los Angeles, and results, a few weeks or years later, in the end of life on Earth as we know it.
Air pollution particles that a pregnant woman inhales have the potential to travel through the lungs and breach the fetal side of the placenta, indicating that unborn babies are exposed to black carbon from motor vehicles and fuel burning, according to a study published in the journal Nature Communications.
Teen activist Greta Thunberg delivered a talking-to to members of Congress Tuesday during a meeting of the Senate Climate Change Task Force after politicians praised her and other youth activists for their efforts and asked their advice on how to fight climate change.
The University of California system will dump all of its investments from fossil fuels, as the Associated Press reported. The university system controls over $84 billion between its pension fund and its endowment. However, the announcement about its investments is not aimed to please activists.