Sodium & Health
What is Sodium & What Does it Do?
Sodium, along with its partner chloride, make up table salt and act as major electrolytes in our bodies.
Sodium levels are kept high outside of our cells while potassium levels are kept high inside our cells. This difference is key to how our nerves communicate, our muscles contract, our digestion moves, and our heart beats. In fact, we spend 20-40% of our resting energy just moving sodium out of our cells and potassium inside. You know an activity is important when it’s that energetically expensive!
Wherever sodium goes, water follows. Since sodium is concentrated outside our cells, water’s little sibling tag-along tendency keeps our tissues plump and juicy and our blood liquid.
Sodium Deficiency:
Low sodium in the blood is called hyponatremia. It is rarely due to not eating enough salt, but is more likely caused by illness or overhydration after heavy sweating.
Our kidneys are obsessively monitoring and controlling the amount of sodium in our blood. They remove excess sodium by transferring it from our blood and into urine when we are too salty. When we need more salt our kidneys instead move more water from our blood and into our urine to concentrate the salt we already have. This balancing act is an intricate hormonal dance involving our kidneys, adrenal glands, and pituitary glands. Salt isn’t quite as simple as it might seem at first glance.
Symptoms of Low Sodium:
Headache
Nausea
Vomiting
Muscle cramps
Fatigue
Disorientation
Fainting
Symptoms of Severe, Rapidly Developed Low Sodium Levels:
Brain swelling
Seizures
Coma
Brain Damage
Death
Causes of Low Sodium Levels:
Inappropriate antidiuretic hormone secretion (pituitary gland hormone)
Excessive water intake after sodium loss through sweat/diarrhea/vomit
Kidney disease
Some medications (listed later in this article)
Sodium Excess:
While low sodium is troublesome, high levels are a much more common problem in the U.S. On a whole, we are simply eating too much salt and drinking too little water. This leads to several different diseases which we will cover in a moment.
Where to Find Sodium:
First, let’s cover sources of sodium; the vast majority of our sodium intake comes from processed food. Naturally occuring foods have very little sodium. For example, an 8 oz bag of unsalted potato chips contains 18 mg of sodium, but the same serving size of salted potato chips has 1,196 mg of sodium - that’s over half the maximum recommended intake for a whole day! (1)
It’s not just the salty snack foods we need to worry about: processed deli meats like sausage, bacon, lunchmeat, hot dogs, and ham all contain hundreds of milligrams of sodium. Even a cup of corn flakes contains 182 mg of sodium; a cup of air popped popcorn only has 1 mg of sodium! (1)
Daily Intake:
How much sodium should we be eating each day? Most people should limit their intake to between 1,500 mg and 2,300 mg a day. Those with chronic illness or who are “sodium sensitive” may do much better with intakes under 1,500 mg daily. (1) To put this into perspective, the average U.S. adult consumed between 3,300 and 4,400 mg daily according to data collected between 2007 and 2010. (1) I wonder what that number is over twelve years later.
One Suggested Strategy
To maintain healthy sodium levels, aim for 500 mg of sodium or less for each of your three meals (or 750 mg if you eat two meals a day), and keep your snack consumption at 800 mg of sodium or less. Don’t forget to count your beverages; the average can of soda contains 22 mg of sodium, canned tomato juice contains around 24 mg, and energy drinks can have over 200 mg of sodium!
If your meal contains more sodium than you would like, be sure to drink a big glass of water to give your kidneys some help eliminating that extra sodium, and don’t forget to load your plate with potassium-rich fruits and vegetables!
You will quickly see how maintaining a healthy sodium intake is difficult when you are eating packaged foods. If you stick with plant-based, whole foods, there is no need to pull your calculator out at meal time – your sodium intake will be nice and low even with a pinch of salt from your shaker.
Toxicity:
Acute sodium toxicity is quite rare, and is almost always due to water loss or dehydration. It should be noted that dehydration and the following symptoms are more common in those with advanced ages. Altered mental function and irritability may be the first noticeable signs, so do try to keep yourself and your loved ones hydrated!
Symptoms of Sodium Toxicity:
Dizziness or fainting
Low blood pressure
Decreased urination
Altered mental status
Lethargy
Irritability
Stupor
Convulsions
Coma
Intracranial bleeding due to brain shrinkage
Prevention of Disease:
Sodium causes disease when consumed in excess. Keeping your sodium levels between 1,500 mg and 2,300 mg can be a major factor in preventing and treating a host of significant diseases.
Diseases that are linked to excessive sodium intake include:
Hypertension (high blood pressure)
Endothelial dysfunction - a precursor to atherosclerosis
Cardiovascular disease - the leading cause of death in the U.S.
Gastric (stomach) cancer
Osteoporosis - excess sodium leaving in the urine takes calcium with it
Kidney stones - from the excess calcium in the urine
Sodium as Treatment?
When sodium or blood volume is low, symptoms can result. Eating some food and drinking water is usually all that is needed.
With those who have a diagnosis of Postural Orthostatic Tachycardia Syndrome (POTS), increased sodium intake can be a necessary part of their treatment. Do be sure to talk with your doctor and obtain a diagnosis prior to treating yourself with extra salt. There is no use trading one problem for another, and salt is only one part of a comprehensive POTS treatment. (2)
Additionally, sodium is used as part of an electrolyte solution in the treatment of dehydration and electrolyte loss due to excessive sweating or continual vomiting or diarrhea.
Medication and Nutrient Interactions:
Sodium intake through sodium bicarbonate (baking soda) has been shown to interfere with the following medications:
Cefpodoxime
Chlorpropamide
Aspirin
Pseudoephedrine
Potassium depleting medications - taking these medications along with sodium bicarbonate can cause low potassium levels
Medications that can lead to low sodium levels include:
Diuretics
NSAIDs - like ibuprofen or naproxen
Opiate medications
Phenothiazines
SSRIs
Tricyclic antidepressants
Applications:
This week, I hope you walk away from this article with the following key points:
Unlike the previous nutrients discussed, sodium excess is much more common than deficiency and linked with several diseases.
The average optimal sodium intake for adults is between 1,500 mg and 2,300 mg - or a bit less than a teaspoon of table salt.
Processed foods are filled with excess sodium and should be avoided as much as possible. Yes, this includes “healthy”, “natural”, and “organic” processed foods. Salt is used as a “natural” preservative to increase the shelf life of packaged foods. Be sure to read labels!
Next week:
Next week, we will wrap up our exploration of individual nutrients with our final article on zinc. We will have traveled from vitamin A all the way to zinc!
To our health!
References:
Higdon, J, “Sodium” Linus Pauling Institute, 2001; last update: 2019; accessed February 16, 2022; https://lpi.oregonstate.edu/mic/minerals/sodium
Benarroch EE. Postural tachycardia syndrome: a heterogeneous and multifactorial disorder. Mayo Clin Proc. 2012 Dec;87(12):1214-25. doi: 10.1016/j.mayocp.2012.08.013. Epub 2012 Nov 1. PMID: 23122672; PMCID: PMC3547546.
