What are electrolytes? Electrolytes are essential minerals that can carry an electric charge when they are dissolved in water. Our bodies need electrolytes because they serve a number of functions and the lack of those functions would shut us down. Electrolytes manage the flow of water in and out of cells to prevent dehydration or overhydration. They generate the electrical currents that let our brains communicate with our muscles. They regulate the body’s pH levels. And they help to move nutrients into cells and waste products out.
Many electrolytes are minerals or salts, but not like the table salt I put on my chips. The main electrolytes in the body are sodium, chloride, calcium, magnesium, bicarbonate, potassium, and phosphate. They are things our bodies need to run, but they are not exclusively in our bodies. An electrolyte is a material that can let ions move and carry an electric charge. The sulfuric acid solution in a car battery is an electrolyte. In a phone battery, the electrolyte usually contains lithium salts in a liquid or gel-like solvent.
An ion is any atom or molecule that has an electric charge, either positive or negative. Atoms are usually neutral because they have the same number of protons and electrons. Protons carry a positive charge, and electrons carry a negative charge, so if they balance the atom is neutral. For example, a sodium atom has 11 protons and 11 electrons. A chlorine atom has 17 protons and 17 electrons. The electrons are arranged in shells, or energy levels, around the nucleus. Sodium has 11 electrons, arranged 2, 8, and 1. That one outer electron is relatively easy to lose because it is far from the nucleus and held less tightly. Chlorine has 17 electrons, arranged 2, 8, and 7. It is close to having a full outer shell, so it can gain one electron. When sodium gives an electron to chlorine, sodium becomes a positive ion, Na⁺, and chlorine becomes a negative chloride ion, Cl⁻. These oppositely charged ions attract each other and form sodium chloride, or table salt.
So, why do we need these in our bodies? Our bodies are mostly water, and water doesn’t conduct electricity very well. In fact, pure distilled water is an excellent insulator because it does not conduct electricity at all. Tap water has a lot of dissolved salts in it, which is why if you drop a toaster in a regular bath, you will be electrocuted. And this is how electrolytes work in our bodies.
Electrolytes help the body regulate fluid because water moves toward areas with more dissolved particles. Sodium is found mostly outside cells, especially in the blood and the fluid around cells. Potassium is found mostly inside cells. The body keeps them in these different places using cell membranes, ion channels, and the sodium-potassium pump. Water can move across cell membranes more easily than many ions can, so if the concentration of dissolved particles is higher on one side of a membrane, water tends to move that way. This is osmosis. Sodium is especially important for controlling the amount of water in the blood and the fluid outside cells, which is why it also affects blood pressure.
Electrolytes allow the brain and nerves to communicate with the muscles. Nerve and muscle cells keep different amounts of sodium, potassium, calcium, and chloride inside them. When a signal is sent from the brain to the muscles, or from the muscles to the brain, the ion channels open and release their ions across the cell membrane, changing the voltage and sending an electrical signal.
Electrolytes regulate pH by absorbing acid. The enzymes and cells in our body need a narrow band of pH to function. Too alkaline or too acidic and they will stop working. Bicarbonate travels round the body in the blood and binds to hydrogen ions to reduce acidity in the blood. The body monitors carbon dioxide and acidity, and the lungs can change how much carbon dioxide we breathe out.
Electrolytes have other functions as well. Without them, our bodies would shut down. So, do you need to drink an expensive sports drink “WITH ELECTROLYTES”? Probably not. Not unless you are exercising in extremely hot weather or exercising for a very long time. We get more than enough electrolytes in the food we eat. A drink of tap water probably has enough electrolytes in it. If you want, you could make your own with a tablespoon of honey, a quarter teaspoon of salt and a little lemon juice. However, if you are severely dehydrated then you do need extra electrolytes. Doctors might give you oral rehydration solution, or in more serious cases, fluids through an IV, which would contain an exact balance of electrolytes and fluids. Diarrhea is still a major killer, especially of young children, because it causes dangerous loss of water and electrolytes, and many people do not have access to clean water or oral rehydration salts. And this what I learned today.
Sources
https://en.wikipedia.org/wiki/Electrolyte
https://www.cedars-sinai.org/stories-and-insights/expert-advice/electrolytes
https://www.bupa.co.uk/newsroom/ourviews/what-are-electrolytes
Photo by Airam Dato-on: https://www.pexels.com/photo/pocari-sweat-electrolyte-beverage-bottles-in-ice-30731008/