Medicine For People!

October 2011

Potassium – The Salty Little Element that Makes Us Go

Seth's blood pressure had been high for years. I'd successfully sold him on the idea of a blood pressure medication. This had been a difficult sell because, as with most people, his high blood pressure caused no symptoms. But after a friend suffered a heart attack, Seth came in and volunteered take his pills.

The trouble was the pill didn't work. We added a second. Still no joy. A third, and his blood pressure still hovered just above the desirable range. His potassium was low, so I urged him to take a potassium supplement. At this he drew the line, one concern being that one of his medications was an ACE inhibitor[1] and the package insert said not to take it with potassium. All my explanations to the contrary couldn't outweigh the fine print on that piece of paper.

One day Seth's pressure surged. He felt terrible and went to emergency room. His potassium level was even lower, and he acceded to potassium administration there. Immediately his blood pressure fell to normal. He's been taking potassium since and feeling better than he's felt in many years.

What's potassium? Why did this happen to Seth?

Elements R Us:The Place of Potassium in the Human Body

Potassium is one of the chemical elements that make up our bodies.   In terms of abundance, it's not one of the top six, which are:

  1. Oxygen
  2. Carbon
  3. Hydrogen
  4. Nitrogen
  5. Calcium
  6. Phosphorus

Potassium is way down at number 7, just above chloride and sodium.    (See entire list).

Potassium, sodium, and chloride form salts. They aren't essential constituents of fats, proteins, or carbohydrates. They don't make up your organs and bones. Instead, you find them dissolved in the fluids of the body. Remember, we're made up of as much as 90 percent water, and all the water in the body is, to one degree or another, salty.

You can rub table salt between your fingers; it's a solid. But drop it into water and it seems to disappear.   The solid particles of sodium chloride become tiny atoms of positively charged sodium and negatively charged chloride.   Dissolve supermarket salt substitute (potassium chloride), and the same thing happens, producing positively charged potassium and negatively charged chloride atoms in the water. You can't see the potassium chloride then, but it, too, gives the water a salty taste.

I Sing the Body Electric:The Role of Potassium in Life Processes

The glass with the salty solution carries no magic, but the same solution in your body, organized by the membranes of your cells, lends electrical charges to those membranes. This holds the key to how you think, how you move, and how your body works. The fats, carbohydrates, and protein in your diet form just the structure of your body. The potassium, sodium, chloride, and several other minerals (chiefly calcium and magnesium), dissolved in water, enable the electrical signals in our salty insides. These electrical signals make us go.

It's All About Membranes

Let's elaborate. Cells make up all our tissues. Each cell has a membrane.  Here's the miracle. Each membrane carries an electrical charge. Take away that charge and we no longer live and move. Maintain the charge on the membranes and we dance and sing and work and love.

Here's an image of a membrane with a positive charge on its left side (its outside) and a negative change inside.


Potassium, Sodium, and the Electric Eel

The main point is that the membrane has an electrical charge, and you can skip to the next paragraph if you want to trust me on this. For you skeptics, the green circles in the image are chloride ions[2] (Cl-), the blue squares sodium ions (Na+), and the pink squares potassium ions (K+). The green arrow across the membrane shows that since there are more green chloride ions on the left, chemical forces make them want to move across the membrane to the right. The membrane, however, resists this movement most of the time and so maintains more positive charges on the outside than the inside. If you could line up 16 of these membranes side by side, you could generate the same voltage you get out of a flashlight battery, albeit with very little current. (Go to considerably more effort, stack up about 5000 of them as does the electric eel, and you would not need to carry a taser for self-protection.)

Again, pumps in the membrane move sodium and potassium to maintain a charge on the membrane. Channels allow sodium and potassium to move across the membrane and allow muscle and nerve function. Here are more illustrations, animations, and tutorials regarding cell membrane electrical activity.

Finally, here is an amazingly beautiful animation of nerve impulses without narrative explanation. You can see the sodium and potassium (with a symbol for their positive charge) dancing through the cell membrane. At the end of the nerve cell, you see the packets of neurotransmitter (such as serotonin) moving across to the next cell and influencing it.

How these Electrical Fields Create Life Processes

For those of you who skipped the last section, you missed the part about the electric eel, but don't worry. You can live to a ripe old age anyway. Just remember that cell membranes and their electrical nature make us dance and sing and work and love. They have minute gadgets (gates and pumps) that do wonderful things. They cause muscles to contract so that you can run and dance. The make nerves send signals so that you can think. Actually, electrical impulses are involved in just about every bodily function, but that's another story, one we touched on here.

Membranes of our nerve and muscle cells operate pretty darn well when we have adequate potassium levels inside our cells and proper levels of potassium outside the cell (in the space between the cells or in the blood).

But when potassium levels are extremely high or low, nerve and muscle function degrades. Muscles grow weak, nerves become erratic, (too excitable in one place, paralyzed in another), and the heart beats irregularly, eventually to the point of fatal failure.

Potassium Deficiency is Common

Potassium deficiency isn't difficult to study. It's common, because potassium is low in the modern diet compared to the diet on which we evolved.

In our next newsletter I will tell you about the causes and results of potassium deficiency and go into some simple ways to make sure you've got enough of this vital element swimming in the salty sea of your body. Then, with luck and plenty of exercise, you'll be able to avoid medication for high blood pressure.

Preservative-Free Flu Vaccine

We have about thirty doses remaining of preservative-free 2011-2012 influenza vaccine. You do not need an appointment if you do not mind a short wait, but we will run out soon so I suggest a phone call first.


[2] When the sodium and chloride in that table salt dissolve in the water, we call the sodium part a sodium ion, and the chloride part a chloride ion, and we use the word "ion" because each part carries an electrical charge.


Medicine for People! is published by Douwe Rienstra, MD at Port Townsend, Washington.