Potassium and Sodium: The Dynamic Duo!

The electrolytes potassium and sodium are two of the most misunderstood minerals in the body. We are told to ‘cut you salt intake’ and ‘eat more vegetables’ to get a balance of sodium and potassium, but all too often we are getting these minerals way out of balance.

People are thought to be getting too much salt, aka sodium, from processed foods, from dining out, and from adding salt to dishes for flavor. The conventional wisdom says ‘this contributes to rising blood pressure’ but is this actually correct?

What are electrolytes?

Sodium and potassium are classed as electrolytes, which are substances that dissociates into ions Na⁺ and K⁺ in solution, making them capable of conducting electricity. Normal body function depends on the tight regulation of potassium concentrations inside and outside cells.

We are inherently electrical beings, conducting micro-electric currents across and through all our cells. This helps to create the correct heartbeat, impulse transmission in the nerves, and muscle contraction throughout the body.

These micro-currents are provided by the potassium/sodium pumps and they’re based within the cell membranes. Up to 40% of the body’s energy expenditure is used up by the sodium-potassium pumps, so it’s critical to get their balance right_1,2.

Potassium is the most important positively charged ion inside cells, whereas sodium is the main ion in the fluid outside cells. Potassium is higher inside the cell with sodium higher outside the cells. This difference in concentration creates what is called a ‘membrane potential’ and this potential is maintained by Na⁺/K⁺ pump which use energy (ATP) to pump sodium out of the cell in exchange for potassium.

The most relevant role of the membrane potential is to keep the central nervous system and electrical firing of nervous impulses correctly balanced. This is vital for life and controlling a myriad of functions in the body. In terms of amounts we need about 1.5g/day of sodium and 4.5g/day of potassium. Why do we need more potassium than sodium I hear you ask?

Ancestral Diets were Potassium Rich

Many years ago, when humans roamed the earth gathering and hunting, potassium was abundant, while sodium was scarce. The so-called Paleolithic diet delivered about 11,000 milligrams (mg) of potassium a day, much of it from fruits, vegetables, leaves, flowers, roots, and other plant sources, but well under 700 mg of sodium. The scarcity of sodium is reflected in the human body’s marvelous ability to hold onto this substance.

Today, sodium is easy to come by, inexpensive, and abundant in our diets. This has been largely driven by the food processing industry adding salt to processed and tinned foods for flavour and preserving the life of the food. The average American consumes between one and three teaspoons of salt a day, or somewhere between 2,500 and 7,500 mg of sodium. That’s far more than the scant 200 mg a day the body needs. It’s a different story for potassium. We average 2,500 mg a day, about half of the 4,700 mg minimum recommended for adults.

This imbalance is actually creating a variety of symptoms and disease states which can go un-noticed. The symptoms include: muscle cramps, kidney stone formation, poor sleeping, fatigue, high blood pressure, bloating/gas issues (due to low stomach acidity), anxiety, high cholesterol, and arrhythmias (irregular heartbeats).

Be aware of modern life stressors – it lowers potassium

In our modern lifestyles today, there’s an increasing array of stressors that affect our bodies, primarily with the increased production of adrenalin and cortisol, which lowers potassium, combine that addictive coffee consumption, acting like a diuretic and you further deplete your potassium. Add in a croissant, a bagel or a chicken fried rice (high carb meals), and your potassium goes way down. This generally goes unnoticed until you see the symptoms discussed or on a more serious level the sympathetic (stress) load on the heart goes high increasing the risk of heart attacks.

Let’s add here, that your body is happy to lose the potassium, because genetically that’s what it used to do many thousands of years ago, with all that abundant potassium around in food it was not a problem. So the sodium:potassium ratio becomes 5:1 or 20:1 in some cases, instead of the ancestral 1:4 ratio.

In my next article I’ll describe the actual diseases you can prevent with potassium, how to replete it, the proper way to test it, and why salt has got such a bad rap – see you in part 2!

References:

1. Sheng H-W. Sodium, chloride and potassium. In: Stipanuk M, ed. Biochemical and Physiological Aspects of Human Nutrition. Philadelphia, PA: WB Saunders Co.; 2000:686–710
2. Brody T. Nutritional Biochemistry. 2nd ed. San Diego, CA: Academic Press; 1999

Written by:

Miles Price

Functional Medicine Practitioner & Clinical Nutritionist

M.Sc Nutritional Therapy, Post-Grad Diploma Functional Medicine Institute of functional medicine & functional medicine University