Electrolyte enhancing is becoming more and more common in the marketing of sport drinks and other health products.
The addition of these substances to bottled water, for example, make the product much more attractive and expensive. But, what exactly are electrolytes? And why are they so popular?
The term electrolytes refers to a number of charged ions floating around in a solution, typically aqueous, which help the human body carry out many of its essential biochemical reactions. In the human body some of the most common electrolytes include- sodium (Na+), chloride (Cl-), potassium (K+), calcium ( Ca2+), magnesium (Mg2+), phosphate (HPO4-), and bicarbonate (HCO3-). All of which have varying, essential roles in the body.
Amongst the many roles that charged ions have in the body is that of cellular communication via the generation of electrical impulses. Some cells in the human body rely on established concentration gradients of ions between their intra- and extra- cellular environments. Neurons and myocardiocytes (heart muscle cells) are good examples, these rely on concentration gradients and on a difference in net charge to carry out electrical impulses known as action potentials.
Action potentials from neurons are essential for the proper function of the central and peripheral nervous systems. Neuronal signaling allows us to use all of our senses, interact with our surroundings, and build memories.
Action potentials carried out by myocardiocytes are responsible for the contractions of heart muscle that make the heart pump blood to the lungs and body. This allows for gas exchange in the lungs and for oxygen delivery to meet metabolic needs.
Hydration at a cellular level is affected by levels of free floating electrolytes found in the blood plasma. As a general rule of chemistry, water will follow the site of where there is the greatest ion/solute concentration (salts and sugars).
This brings forth the topic of cellular tonicity, which refers to the cell shape and levels of salt found inside the cell compared to the outside. If the there is a greater concentration of salts inside the cell, water will flow inward and cause the cell to swell. Such cells are said to be hypertonic to their external environment. If the extracellular environment has a higher concentration of ions compared to the inside of the cell, then water leaves the cell and it shrivels. This cell is said to be hypotonic to its external environment.
A cell is isotonic to its external environment when salt concentrations both inside and outside the cell membrane are equal. Regulatory mechanisms to prevent dehydration rely heavily on this relationship between electrolytes and cellular tonicity!
Charged molecules cannot freely pass through the cell membrane and so intracellular salt concentration is monitored by channel proteins that regulate ionic traffic flow. This cellular behavior comes into play when the body is dehydrated or suspects dehydration.
In order to conserve water the body will start to retain salts, to ensure that a higher concentration of water will remain in the body. Other physiological mechanisms also take effect, the posterior pituitary will release vasopressin, commonly known as ADH (or Antidiuretic Hormone), to increase the reabsorption of water by the kidney and a constrict blood vessels.
It is important to recognize that proper hydration is much than simply drinking water, it involves a complex internal interaction between ions, sugars, carbohydrates, cells, blood plasma and other more complex organ systems. But drinking water is a good start! For more recommendations on healthy electrolyte balance in the body receive a nutritional profile from CORE for only 79!
Salts and the Heart
It is common to hear that individuals with heart and/or circulatory problems have to watch their salt intake. It is often the case that the body will interpret certain heart conditions, like congestive heart failure (HF), as dehydration.
Misinterpretation of HF leads to the activation of the renin-angiotensin aldosterone system which causes the movement of ions back into the blood thus retaining more water. Complications of HF include increased blood pressure, pulmonary edema, and cardiac muscle hypertrophy (enlargement of the heart muscle). For this reason individuals with heart conditions are given diuretics and their salt intake is closely monitored. How the body makes use of electrolytes has huge effect of hydration and general health.
Sweat and Sport Drinks
Have you ever tasted your own sweat? If your have, you know of the salty flavor it has.
This is because sweat is not just composed of water, but also electrolytes. This is especially true for individuals who work out in the heat and sweat more as a result.
Athletes frequent the use of sports drinks such as Gatorade or Powerade, which are designed to not only replace water loss during exercise but also electrolytes and carbohydrates to ensure proper hydration and energy recovery.