Bananas are one of the most widely consumed fruits in the world for good reason. The curved yellow fruit packs a big nutritional punch, wrapped in its own convenient packaging. Some scientists believe that the banana may have even been the world's first fruit.
Dan Koeppel, author of Banana: The Fate of the Fruit That Changed the World, traces the banana back to the Garden of Eden, where he believes it was the banana, not the apple, that was the "forbidden fruit" that Eve offered Adam.
Today, bananas are grown in at least 107 countries and are ranked fourth among the world's food crops in monetary value. Americans consume more bananas than apples and oranges combined.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods, which can be found here.
Nutritional breakdown of bananas
One medium banana (about 126 grams) is considered to be one serving. One serving of banana contains 110 calories, 30 grams of carbohydrate and 1 gram of protein. Bananas are naturally free of fat, cholesterol and sodium.2
Bananas provide a variety of vitamins and minerals:
- Vitamin B6 - .5 mg
- Manganese - .3 mg
- Vitamin C - 9 mg
- Potassium - 450 mg
- Dietary Fiber - 3g
- Protein - 1 g
- Magnesium - 34 mg
- Folate - 25.0 mcg
- Riboflavin - .1 mg
- Niacin - .8 mg
- Vitamin A - 81 IU
- Iron - .3 mg
The recommended intake of potassium for adults is 4700 milligrams per day.
Possible health benefits of bananas
Blood pressure: Maintaining a low sodium intake is essential to lowering blood pressure, however increasing potassium intake may be just as important because of its vasodilation effects. According to the National Health and Nutrition Examination Survey, fewer than 2% of US adults meet the daily 4700 mg recommendation.3
Also of note, a high potassium intake is associated with a 20% decreased risk of dying from all causes.3
Asthma: A study conducted by the Imperial College of London found that children who ate just one banana per day had a 34% less chance of developing asthma.
Cancer: Consuming bananas, oranges and orange juice in the first two years of life may reduce the risk of developing childhood leukemia. As a good source of vitamin C, bananas can help combat the formation of free radicals known to cause cancer. High fiber intakes from fruits and vegetables like bananas are associated with a lowered risk of colorectal cancer.
Heart health: The fiber, potassium, vitamin C and B6 content in bananas all support heart health. An increase in potassium intake along with a decrease in sodium intake is the most important dietary change that a person can make to reduce their risk of cardiovascular disease, according to Mark Houston, MD, MS, an associate clinical professor of medicine at Vanderbilt Medical School and director of the Hypertension Institute at St Thomas Hospital in Tennessee.3
In one study, those who consumed 4069 mg of potassium per day had a 49% lower risk of death from ischemic heart disease compared with those who consumed less potassium (about 1000 mg per day).3
High potassium intakes are also associated with a reduced risk of stroke, protection against loss of muscle mass, preservation of bone mineral density and reduction in the formation of kidney stones.3
Diabetes: Studies have shown that type 1 diabetics who consume high-fiber diets have lower blood glucose levels and type 2 diabetics may have improved blood sugar, lipids and insulin levels. One medium banana provides about 3 grams of fiber.
The Dietary Guidelines for Americans recommends 21-25 g/day for women and 30-38 g/day for men.
Treating diarrhea: Bland foods such as apple sauce and bananas are recommended for diarrhea treatment. Electrolytes like potassium are lost in large quantities during bouts of diarrhea and may make those affected feel weak. Bananas can help to promote regularity and replenish potassium stores.
Preserving memory and boosting mood: Bananas also contain tryptophan, an amino acid that studies suggest plays a role in preserving memory and boosting your mood.
Incorporating more bananas into your diet
Fresh bananas are available year-round. Unlike other fruits, the ripening process of bananas does not slow down after they are picked. Bananas should be stored at room temperature. The warmer the temperature, the faster bananas will ripen. However, to slow ripening, bananas should be refrigerated. The outer peel of the banana will darken but the banana itself will stay intact longer.
Add a sliced banana to your morning cereal or oatmeal for a more nutritious breakfast
To encourage faster ripening, place the banana in a brown paper bag at room temperature.1
In 2008, a popular diet fad known as the Morning Banana Diet recommended eating a banana in the morning along with water, eating a normal lunch and having dinner before 8pm.
Like apple sauce, ripe mashed bananas can be used in baked goods to replace oil or butter. Mashed bananas lend a moist, naturally sweet flavor to muffins, cookies and cakes.
Peel and freeze bananas for a great addition to any smoothie.
Add sliced banana to your morning cereal or oatmeal, or take a banana with you on your way to work or school for a healthy, portable snack.
Risks and precautions
Beta-blockers, a type of medication most commonly prescribed for heart disease, can cause potassium levels to increase in the blood. High potassium foods such as bananas should be consumed in moderation when taking beta-blockers.
Consuming too much potassium can be harmful for those whose kidneys are not fully functional. If your kidneys are unable to remove excess potassium from the blood, it could be fatal.
Dr. Peter S. Gelfand, who practices Internal Medicine in Long Beach NY, says:
"Certain medications used for heart disease and hypertension have the potential to increase potassium levels. Examples include certain Beta blockers such as Labetalol, medications that work by blocking the actions of the hormone Aldosterone such as Lisinopril and Losartan ; And certain Diuretics like Spironolactone and Eplerenone. This is a partial list only, and you should consult with your doctor if potassium levels become a concern."
Recent developments on bananas from MNT news
A study by researchers at the University of Brazil and published in the Journal of the Academy of Nutrition and Dietetics reveals that a new gluten-free pasta, derived from the flour of green bananas is a healthier, delicious substitute compared to other pastas for celiac disease patients.
To the surprisingly inventive uses for banana peels - which include polishing silverware, leather shoes, and the leaves of house plants - scientists have added purification of drinking water contaminated with potentially toxic metals. Their report, which concludes that minced banana peel performs better than an array of other purification materials, appears in ACS's journal Industrial & Engineering Chemistry Research.
Written by: Megan Ware, RDN, LD, registered dietitian and nutritionist