Bananas are fat- and cholesterol-free, low in calories and rich in vitamin C, dietary fiber, potassium and a variety of antioxidant compounds. Including nutrient-dense foods like bananas in your diet regularly may help prevent several chronic diseases. Available in hundreds of varieties, bananas are the most commonly eaten fruit in the United States, with Americans consuming approximately 26 pounds of them per person annually. If you are allergic to latex, speak to your doctor before eating bananas. Bananas contain proteins that are similar to those in latex and can cause a potentially serious reaction in people with a latex allergy.
A single, medium-sized banana weighing about 126 grams contains 11 milligrams of vitamin C. This amount supplies 15 percent of the U.S. Department of Agriculture's recommended daily allowance of vitamin C for men and women averaging 2,000 calories daily. Vitamin C supports immune system health and helps repair and maintain skin, blood vessels, cellular tissue, teeth and bones. It also has antioxidant properties that may allow it to stop free radical compounds from damaging DNA and aid in the prevention of heart disease, osteoarthritis, cancer and high blood pressure. The vitamin C content of bananas decreases when the fruit is exposed to heat, light or air. Store bananas in a cool, dry place and use them within three to four days of purchase.
Eating a medium-sized banana provides you with 12 percent of the dietary fiber that you need for the day. Bananas contain both soluble and insoluble fiber, but have an especially high amount of insoluble fiber. Insoluble fiber, which does not break down as it passes through the digestive tract, may help regulate bowel movements and decrease the risk of digestive system disorders. Registered dietitian Rita Carey Rubin adds that eating plenty of high-fiber foods like bananas may also lessen the risk of osteoporosis, obesity and heart disease.
Bananas are well known for being rich in potassium for good reason -- each medium-sized banana supplies 451 milligrams of potassium, or 9.5 percent of the RDA of the mineral. Potassium helps activate enzymes vital for adenosine triphosphate, or ATP, synthesis and energy metabolism. It is an electrolyte as well as a mineral and helps maintain skeletal, smooth and cardiac muscle contractions. Adequate potassium intake from foods like bananas can decrease the risk of osteoporosis, kidney stones and stroke. If your diet is high in sodium, your body may require more potassium than normal to keep the minerals in balance. Eat potassium-rich foods daily and talk to your doctor about ways to lower your sodium intake.
In 2008, a study published in the medical journal "Fitoterapia" examined the amount of active antioxidants in bananas. The researchers determined that rats fed a diet containing bananas had higher levels of the antioxidant compounds superoxide dismutase, catalase and glutathione than rats not fed bananas. Superoxide dismutase breaks down free radicals, and catalase is an enzyme that protects cells by degrading excess hydrogen peroxide. Glutathione, which Mark Hyman, M.D., calls one of the most powerful of all antioxidants, may play a critical role in preventing cancer and infections.
- Fruits & Veggies More Matters: Banana - Nutrition, Selection, Storage
- USDA National Nutrient Database for Standard Reference: Nutrient Data for 09040, Bananas, Raw
- Linus Pauling Institute: Potassium
- Fitoterapia: Antioxidant Activity of Banana Flavonoids
- Better Health Channel: Latex Allergy
- University of Maryland Medical Center: Vitamin C (Ascorbic Acid)
- ABC News: Preserving Vitamin Content in Foods
- Harvard University Health Services: Fiber Content of Food in Common Portions
- Today's Dietitian: Dietary Fiber - New Insights on Health Benefits
- PopSci: Can This Fruit Be Saved?
- bananas image by Maria Brzostowska from Fotolia.com