Much Ado About Aldosterone: Electrolyte Imbalance and the Craving for Salt
July 11, 2014 | Published by Dr. James L. Wilson
Aldosterone is responsible for the maintenance of fluid (water) and the concentration of certain minerals (sodium, potassium, magnesium and chloride) in the blood, the interstitial fluid (area between the cells) and inside the cells. In the blood, sodium is the most dominant of the four minerals. Inside the cells, potassium has the highest concentration. These minerals are called electrolytes because they carry minute electrical charges. These electrolytes are very important for proper cell function and fluid properties and they must remain in a relatively constant ratio to each other. Small deviations in ratio or to concentration means alterations in the properties of the fluid, the cell membrane and the biochemical reactions within the cell. In fact, most of the physiological reactions in the body depend in some way on the flow or concentration of electrolytes.
In times of stress, aldosterone is the major director of these relationships by its influence on sodium and water concentrations. As the concentration of aldosterone rises, the concentration of sodium rises in the blood and interstitial fluid. As mentioned above, aldosterone controls sodium, potassium and fluid volumes in your body. When aldosterone secretions are normal, potassium, sodium and fluid levels are also normal. When aldosterone is high, sodium is kept high in the fluids circulating in your body.
However, as circulating aldosterone levels fall, sodium is removed from your bloodstream as it passes through the kidneys and is excreted in the urine. When sodium is excreted it takes water along. Initially, there is some loss of volume of your body fluids but it does not become severe until your circulating sodium level drops to about 50% of its original concentration in body fluids. At this point, even a small loss of sodium begins to have severe consequences.
When the blood’s sodium supply is not replenished by eating salt-containing foods or liquids, sodium and water is pulled from your interstitial fluids into the blood to keep levels from getting too low. If too much salt or fluid is pulled from the interstitial fluids, the small amount of sodium in the cells begins to migrate out of the cells into the interstitial fluid. The cell does not keep a great reserve of sodium in order to maintain its 15:1 ratio of potassium to sodium. As the sodium is pulled from the cell, water escapes as well. This leaves the cell dehydrated and sodium deficient. In order to keep the sodium/potassium ratio constant inside the cell, potassium begins to migrate out in small quantities. However, each cell has minimum requirements for the absolute amounts of sodium, potassium and water necessary for its proper function. Cell function suffers when these requirements are not met, even if the proper ratio is maintained.
If you have an electrolyte imbalance, you must be careful how you rehydrate yourself. Drinking lots of water or liquid without adequate sodium replacement can make you feel worse because it further dilutes the amount of sodium in your blood. Moreover, your cells need salt to absorb fluids. When you are already low on body fluids and electrolytes, try adding salt to your water (about 1/4 teaspoon). Sea salt is a better choice than regular table salt because it contains trace amounts of minerals in addition to the sodium.
When your aldosterone levels are low and you are dehydrated and sodium deficient, you may also crave potassium because your body is sending you the message that your cells are low on potassium as well as sodium and water. However, after consuming only a small amount of potassium containing foods or beverages, you will probably feel worse because the potassium/sodium ratio will be further disrupted. Avoid soft drinks or electrolyte-rich sports drinks because they are high in potassium and low in sodium, which only add to the imbalance. Further, most ‘hydration’ drinks and sodas contain artificial colors, additives, and unhealthy sweeteners. You are much better off having a glass of water with salt in it, or eating something salty with water to help replenish both sodium and fluid volume.
About the Author: With a researcher’s grasp of science and a clinician’s understanding of its human impact, Dr. Wilson has helped many physicians understand the physiology behind and treatment of various health conditions. He is acknowledged as an expert on alternative medicine, especially in the area of stress and adrenal function. Dr. Wilson is a respected and sought after lecturer and consultant in the medical and alternative healthcare communities in the United States and abroad. His popular book Adrenal Fatigue: The 21st Century Stress Syndrome has been received enthusiastically by physicians and the public alike, and has sold over 400,000 copies. Dr. Wilson resides with his family in sunny Tucson, Arizona.
Categorised in: Effects of Stress