Salt: How Much is Too Much?

Recently I was surprised when a patient who was newly diagnosed with hypertension (high blood pressure) mentioned that she had not been advised to cut back on salt, even after consulting with a nutritionist. This is concerning, as, according to the CDC, it is estimated that 90 percent of Americans ages 2 years and above consume too much salt (sodium), and that 2.5 million deaths around the world could be prevented if our salt consumption was reduced to meet the levels recommended by the World Health Organization (WHO).

Salt and Sodium
The words “table salt” and “sodium” are often used interchangeably, but they do not mean the same thing. Table salt (also known by its chemical name, sodium chloride) is a crystal-like compound that is abundant in nature. Sodium is a mineral, and one of the chemical elements found in salt. (Source here)

Although our bodies need sodium, there is much confusion about how much is healthy. The recommended adequate intake for ages 14 and above is about 1500mg of sodium (2/3 teaspoon of salt). Many Americans consume in excess of 3000mg of sodium daily. However, in order to reduce the risk of chronic disease it is advised to reduce sodium intake to less than 2300mg daily (Chronic Disease Risk Reduction Intake).

1500mg of Sodium – 2/3 teaspoon of salt
(about 3800mg of salt)

2300mg of Sodium – 1 teaspoon of salt
(about 5900mg of salt)

Salt and Disease

Even for those with normal blood pressure, salt and sodium have a negative impact on the brain, heart, gut and our overall health. A high salt intake is associated with cardiovascular disease, kidney disease and osteoporosis. Reducing salt has a favorable impact on health and can decrease blood pressure levels within weeks. Studies show that people living in countries where salt consumption is low do not experience the same increase in blood pressure with age that we do in the United States.

Mechanisms

It is well known that sodium attracts water, and a high-sodium diet draws water into the bloodstream, which can increase the volume of blood and subsequently your blood pressure.

Lesser known impacts of excess sodium:

  • increased arterial stiffness
  • increase calcium loss from bones
  • damage to the endothelial and autonomic/sympathetic nervous systems
  • negative impact on our microbiome

Foods

Most of the sodium in our diets does not come from salt we add with a salt shaker, but from foods that are processed and commercially prepared. As a food ingredient sodium has many uses, such as curing meat, baking, thickening, retaining moisture, enhancing flavor (including the flavor of other ingredients) and as a preservative. Some common food additives—like monosodium glutamate (MSG), sodium bicarbonate (baking soda), sodium nitrite and sodium benzoate—also contain sodium and contribute (in lesser amounts) to the total amount of “sodium” listed on the Nutrition Facts label. Surprisingly, some foods that don’t taste salty can still be high in sodium, which is why using taste alone is not an accurate way to judge a food’s sodium content. For example, while some foods that are high in sodium (like pickles and soy sauce) taste salty, there are also many foods (like cereals and pastries) that contain sodium but don’t taste salty. Also, some foods that you may eat several times a day (such as breads) can add up to a lot of sodium over the course of a day, even though an individual serving may not be high in sodium. (Source: FDA)

Check the Package for Nutrient Claims

You can always check for nutrient claims on food and beverage packages to quickly identify those that may contain less sodium. Here’s a guide to common claims and what they mean:

What It SaysWhat It Means
Salt/Sodium-FreeLess than 5 mg of sodium per serving
Very Low Sodium35 mg of sodium or less per serving
Low Sodium140 mg of sodium or less per serving
Reduced SodiumAt least 25% less sodium than the regular product
Light in Sodium or Lightly SaltedAt least 50% less sodium than the regular product
No-Salt-Added or UnsaltedNo salt is added during processing–but these products may not be salt/sodium-free

Prevention is Best

As an Integrative Physician, my interest is of course to help those with hypertension and reduce burden of disease, but mainly to prevent hypertension and other ailments such as heart disease and osteoporosis before they become chronic. Our bodies need salt, but it is important to me to provide ways to start thinking about salt intake and provide strategies to keep sodium intake at a healthy level. For easy tips to reduce sodium, click here.


Worth Reading

Anderson, Cheryl, Campbell, Norm R. C., He, Feng J. He, et al., Effect of dose and duration of reduction in dietary sodium on blood pressure levels: systematic review and meta-analysis of randomised trials, BMJ/2020

Anrather, Josef, Faraco, Giuseppe, Hochrainer, Karin, et al., Dietary salt promotes cognitive impairment, Nature/2019

Centers for Disease Control and Prevention, Heart Disease/Sodium, www.cdc.gov/2021

Coruzzi, Paolo, Grillo, Andrea, Parati, Gianfranco, et al., Sodium Intake and Hypertension, NCBI/2019

Getz, Carly, Sodium: How much is too much?, A Healthier Michigan/2013

Harvard School of Public Health, Salt and Sodium, www.hsph.harvard.edu

Higdon Ph.D., Jane, Sodium (Chloride), Linus Pauling Institute of Oregon State University/2001-2019

Lennon, Shannon L., Smiljanec, Katarina, Sodium, hypertension, and the gut: does the gut microbiota go salty?, NCBI/2019

Prados, Andreu, Is it time to cut down on salt for gut microbiome health? A new randomized controlled trial shows dietary sodium reduction is good for both the gut microbiome and blood pressure, Gut Microbiota for Health/2020

Weill Cornell Medicine, High-salt diet promotes cognitive impairment through the Alzheimer-linked protein tau: New study in Nature finds that a high-salt diet may negatively affect cognitive function in pre-clinical setting, ScienceDaily/2019.

World Health Organization, Salt reduction, www.who.int/2020

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