Electrolytes are as critical for the healthy functioning of the body as any other essential nutrient. They facilitate metabolic processes at the cellular level, and help proteins, carbohydrates, fats, vitamins and antioxidants to do their work. Mineral salts like sodium chloride, or common salt, which dissolve and dissociate in water into positively and negatively charged ions (sodium gets positively charged and chloride, negatively) are known as electrolytes.
These charged ions improve the electrical conductivity of water (pure water by itself is a bad conductor), and ensure that two-thirds of the body’s fluid is retained inside the cells and one-third outside the cells for optimal metabolic functioning. Mineral salts like potassium, calcium and magnesium are positively charged electrolytes. Some of the negatively-charged electrolytes are chloride, bicarbonate, phosphate and some proteins. Because they play such vital roles, electrolytes are present everywhere in the body—in blood, tissues and cells.
These mineral salts and electrolytes are present in a wide variety of healthy foods, albeit in small amounts. A nutritional deficiency of electrolytes is rare and is primarily caused by events that lead to electrolyte imbalances. These include vomiting, diarrhoea, burns, or heavy sweating of a great deal of fluids from prolonged exposure to heat and humidity. Electrolytes that get lost in this way can be replaced easily by drinking cool water (add ORS if you have suffered a severe bout of vomiting or diarrhoea) and eating normal food.
So it’s not the deficiency that is an issue, it’s the balance of electrolytes. Too little or too much of a mineral can both cause problems, disrupting neural functioning, muscle functioning, or even the cardiovascular system.
Research published in the Archives of Internal Medicine in the US in 2011 clearly indicated that a high intake of sodium, common in salty food and processed food, and low intake of potassium (found in fruits and vegetables) leads to a significantly higher risk of cardiovascular disease as well as total mortality from all causes.
While calcium and magnesium work to facilitate muscle contraction, nerve impulse transmission and fluid balance, maintaining a healthy sodium-potassium balance is also important for the integrity of cell walls. The “sodium-potassium pump” is a mechanism that regulates the flow of fluid inside and outside the cell across the cell wall by transporting electrolytes from outside the cell membrane to the inside. Excessive sodium (also known as hypernatremia) in the extracellular fluid (fluid outside cells) can draw out fluid from inside cells and cause cell walls to collapse, and this in turn upsets several metabolic processes. On the other hand, very little potassium inside the cells can upset the sodium-potassium balance and can draw too much water inside the cells, causing them to rupture.
The most common cause of these imbalances is a diet high in processed foods, like potato chips, instant soups, instant noodles, cereals and cornflakes, or junk food like hamburgers, pizzas, pickles and cured or smoked meats, all of which contain very high levels of sodium, and little or no potassium. Excessive intake of table salt or soy sauce also leads to high levels of sodium in the body.
Potassium, on the other hand, is found in meats, milk, fruits, vegetables, grains, and legumes and is absent in processed food. Significant sources of calcium are found in dairy, small fish with bones like sardines, tofu, and vegetable greens. Good sources of magnesium are nuts, legumes, wholegrains, dark green vegetables, seafood, chocolate, and cocoa.
The solution is simple. Cut down on processed and junk food, eat balanced meals full of vegetables, fruits, proteins and wholegrains. Processed foods contain much more sodium than the body can deal with. Sodium in processed foods is in the form of sodium bicarbonate (bicarbonate adds taste, colour, has binding properties, increases the shelf life of the sodium and is an acidity regulator) and not sodium chloride. Which means that your processed snack is full of sodium even if it doesn’t taste very salty.
It is important to note here that the more processed the food, the higher the sodium content; and prolonged excessive sodium intake could lead to hypertension and oedema. When sodium intakes increase, potassium levels naturally decrease, since most of your calories are coming from processed foods. Prolonged potassium deficiencies, called hypokalemia, can lead to muscle weakness, paralysis and mental confusion.
Madhuri Ruia is a nutritionist and Pilates expert. She runs InteGym in Mumbai, which advocates workouts with healthy diets.