In addition to carbohydrates, proteins, fats, vitamins and minerals, your body needs special substances known as electrolytes to function properly. Bananas are rich in the electrolyte potassium, so they can help prevent or treat cases of low blood potassium, also known as hypokalemia. Bananas also have small levels of other electrolytes.
Electrolytes is a term used to describe different elements that, when dissolved in bodily fluids such as your blood, carry an electrical charge. Electrolytes are needed for chemical reactions in the body to work properly. Cells can also control electrolyte concentrations to create electrical charges; this is especially important for muscle and nerve cells, which routinely generate electrical currents. Important electrolytes include sodium, potassium, calcium, magnesium, phosphorus and chloride.
Electrolytes in Bananas
Bananas contain many different electrolytes. According to the U.S. Department of Agriculture National Nutrient Database, a 100 g serving of banana, which is roughly the size of one small banana, contains 1 mg of sodium, 5 mg of calcium, 27 mg of magnesium, 22 mg of phosphorus and 358 mg of potassium. It is generally recommended that adults consume 4,700 mg of potassium each day, so bananas represent an important source of this electrolyte.
Consequences of Low Potassium
If the amount of potassium in your blood gets too low, you will develop a condition known as hypokalemia. Hypokalemia can cause fatigue, constipation and muscle weakness and spasms because your muscle cells will not be able to work effectively. You may also develop abnormal heart rhythms and paralysis, which can affect the muscles that help you to breathe. In severe cases your muscle cells may break down.
Although bananas contain other electrolytes, they are highest in potassium. This means that you will need to eat other foods to avoid imbalances of other electrolytes, such as sodium. Electrolyte imbalances can also occur if you lose large amounts of electrolytes due to excessive sweating or vomiting, or if you use diuretic medications. Talk to your doctor if you are concerned about low levels of any electrolyte.