Nutritional Properties of Banana
A medium-sized banana contains about 422 mg of potassium, an essential mineral for cell function and tissue and organ development, function and growth. Potassium is also necessary for healthy hearts and bones, muscle contraction and digestion, and is an electrolyte, providing the means for electrical impulses to travel along the nerves. Excessive sodium intake, malnutrition, sweating, vomiting, diarrhea, Crohn’s disease and diuretics can cause potassium deficiency. Older people may be at risk of too much potassium because their kidneys are not able to excrete it efficiently. However, most healthy people should strive to get a good balance of dietary potassium through foods like bananas.
A banana supplies about 20 percent of the recommended daily allowance for vitamin B-6, one of the important B-complex vitamins. Vitamin B6 is essential to protein and red blood cell metabolism, the nervous system, and the conversion of the amino acid tryptophan to the vitamin niacin. It supports the thymus, lymph nodes and spleen, which manufacture the white blood cells necessary for a healthy immune system. Vitamin B-6 is not synthesized by the body, so you must get it from dietary sources like bananas.
Fiber is necessary to a well-functioning gastrointestinal system. Getting enough dietary fiber means a reduced risk of constipation, hemorrhoids, heart disease and diabetes. Bananas are rich in soluble fiber, which slows digestion and binds substances like starch and sugar so your intestines don’t absorb too much. The recommended daily intake of fiber is 25 to 30 grams. Replacing processed or white flour with whole grains and eating more fruits and vegetables are the best way to raise your fiber intake, although psyllium husks and flaxseeds can be used as supplements if needed. A single, medium banana contains about 3 g of fiber, about 10 percent of your daily requirement.
Dietary carbohydrates have gotten a bad reputation due to many weight-loss programs that promote severely reducing or eliminating them from your diet. However, complex carbohydrates like whole grains — as opposed to simple carbohydrates like white flour and sugar — and simple carbohydrates from natural sugars like fruits are a necessary part of a healthy diet. The body needs carbohydrates for fuel. Between 40 and 60 percent of your daily calories should come from complex carbohydrates and natural sugars. A medium-sized banana offers 27 g of carbohydrates.
- National Agricultural Library Database: Banana, Raw
- University of Maryland Medical Center; Potassium; Steven D. Ehrlich; May 2009
- Office of Dietary Supplements: Dietary Supplement Fact Sheet — Vitamin B6
- University of Maryland Medical Center; Fiber; David Zieve; Feb. 2010
- Medline Plus; Carbohydrates; June 2011