Electrolytes

Major electrolytes are Sodium, Chloride and Potassium. Electrolytes function to maintain homeostasis, balance in the body.

Electrolytes containing positive and negative charges create currents that move nutrients in and out of cells. They also maintain an adequate level of water inside and outside the cells.

When a particle passes through a membrane, it is called diffusion and when water passes through a membrane, it is called osmosis. This happens in all the cell membranes. For example, when you spend too much time in a pool or the sea, our fingers look wrinkled; this occurs because of osmosis. When our body or cells are exposed to a liquid more salty than the fluids within our body, the body looks for a balance of concentrations. Then, the water comes out of our cells to balance the fluid in which they are immersed and that which is found within the body.

The above image shows what happens inside our cells. Whether cells have plenty of water inside or outside, the electrolytes are responsible for maintaining a balance, otherwise cellular processes stop.

The cells are primarily negatively charged because they contain the chloride ion. Outside the cells positive electrolytes such as sodium ion are found. Sometimes our cell membranes don’t allow particles to pass (diffusion), but water passes freely through the membrane (osmosis). Thus the water will travel to where the concentration of ions is higher and consequently a balance is maintained.

For example, the nerve impulse is a message that tells the muscles to move. With the entry of sodium into the cell and a potassium efflux, the current and the message can be transmitted. It is critical that we have the necessary amounts of potassium and sodium; otherwise the body does not function properly.

Sodium

Sodium is found mainly in table salt, it is used as flavoring and preservative agent. However, large amounts of sodium can have devastating effects on the human body.

All the salt we eat is absorbed by the digestive tract. As explained earlier, if there is a body liquid with too much sodium concentration, the water will move to that place to maintain a balance. That's why eating too much salt increases blood pressure. Sodium ions are dissolved in the blood and in large amounts make water travel out of the cell and into the blood; increasing blood volume and blood pressure rises.

Sodium is found mainly outside the cells and it:

Regulates the transport of fluids
Helps the heart and skeletal muscle relax
Transmits nerve impulses
Regulates blood pressure

The kidneys are responsible for filtering any excess of electrolytes in the body. Normally excess sodium is excreted, but when the kidneys are damaged, sodium retention happens. There are also people who are sensitive to sodium and cannot get rid of the excess causing heart disease, hypertension and kidney disease.

How to know if you are sensitive to sodium?

Family history may give a clue, if your relatives control their blood pressure with diuretics or diets low in salt, it is likely to you can become sensitive to sodium.

Healthy people usually have no problems with sodium. However, moderation is recommended because in the future you can develop hypertension due to sodium sensitivity.

How can you decrease sodium intake?

Eat fresh produce in its original form
Avoid eating processed foods such as sausages, bacon or cured meats
Cook with different species like lemon, pepper, garlic or vinegar
Read the Nutrition label
Avoid ketchup, pickles, olives and salad dressing
Try to buy products low in salt

Taste buds can adapt if you lower salt in your diet and if you decrease consumption, they will adapt to the change.

You should consume 2.4 grams of sodium per day.

Potassium

Potassium has similar functions to those of sodium, but is mainly found inside the cells.

Potassium:

Regulate fluids and mineral transport in and out of the cells
Maintains blood pressure
Transmits nerve impulses
Helps muscle contraction

Most food sources contain potassium. The main ones are:

Bananas
Orange juice
Beans
Yogurt
Broccoli
Peaches
Potatoes

The healthy people usually do not suffer potassium deficiencies, however, when you vomit, have diarrhea or use laxatives for long periods of time, potassium is decreased.

Like sodium, potassium is excreted by the kidneys; therefore harmful effects of potassium are not common. Too much can cause arrhythmias.

Consuming 2-3 grams per day of potassium is recommended

Bibliography:

"ChooseMyPlate.gov." ChooseMyPlate.gov. N.p., n.d. Web. 02 Sept. 2014. <http://www.choosemyplate.gov/>.
Champe, Pamela C., Richard A. Harvey, and Denise R. Ferrier. Biochemistry. Philadelphia: Lippincott/Williams & Wilkins, 2005.
"Fruits & Veggies More Matters." Fruits Veggies More Matters. N.p., n.d. Web. 05 Sept. 2014. <http://www.fruitsandveggiesmorematters.org/>.
Guyton, Arthur C., and John E. Hall. Textbook of Medical Physiology. Philadelphia: Elsevier Saunders, 2006.
Larson, Roberta. American Dietetic Association Complete Food and Nutrition Guide. New Jersey: John Wiley & Sons, Inc., 2002.
Rinzler, Carol Ann. Nutrition for Dummies. Indianapolis, IN: Wiley Pub., 2006.
Wardlaw, Gordon M., and Anne M. Smith. Contemporary Nutrition: A Functional Approach. Boston: McGraw-Hill, 2009.