Before we start discussing the health benefits of bananas, here is some nutritional information for a serving of banana (source - these numbers can be slightly different when obtained from a different source):
Serving size = 1 medium sufficiently ripe banana [about 7″ long and 126 grams (0.28 pounds) in weight]
Total Fat = 0 g; Cholesterol = 0 g; Calories = 110
Potassium = 400 mg (10% of daily recommended value)
Dietary Fiber = 4 g (16% of daily recommended value)
Sugar = 14.8 g; Protein = 1 g (2% of daily recommended value)
Vitamin C = 16% of daily recommended value
Vitamin B6 = 20% of daily recommended value
With this nutritional information in the background let’s work through the incredible health benefits of this commonplace fruit. I will try and list only substantiated facts with references wherever possible. I am particularly concerned about this because there have been some unsubstantiated claims (rumors) about extraordinary banana benefits floating around the internet (here is an example).
- Bananas are good for your heart and nerves: Bananas contain a high dose of potassium - an essential ingredient to keep your heart and nervous system in good shape. Potassium is essential for proper muscle contraction and hence plays an important role in muscle-influenced activities including: the normal rhythmic pumping of the heart, digestion, muscular movements, etc., Some studies have also linked low potassium intake to high blood pressure and increased risk of stroke. Most Americans don’t get enough potassium in their diet (recommended dose is about 4 g per day) - blame it on our fast food culture. Including a banana (or two) in your diet everyday would take you a step closer towards getting your daily recommended dose of potassium (references: American Heart Association, University of Maryland Medical Center, Colorado State University).
- Bananas are good for your kidneys and bones: Benefits to the kidneys and the bones are again due to the high potassium content of bananas. A normal intake of potassium suppresses calcium excretion in the urine and minimizes the risk of kidney stones. Also, for the same reason (suppressing of calcium excretion), it minimizes the loss of calcium from the body and thereby reduces the risk of osteoporosis (references: University of Maryland Medical Center, University of Kansas Medical Center).
- Bananas can act as mood enhancers or mild sedatives: Bananas contain tryptophan (although it’s not one of the major sources, a medium still contains about 10.6 mg of tryptophan). Tryptophan is one of the 20 amino acids which are building blocks of proteins (btw, an incredible number of articles on the internet call tryptophan as a “mood-enhancing protein” and that is technically not correct). Tryptophan helps the body to produce serotonin - which has a calming effect on the brain (creates a stable mood) and acts as a mild sedative. It should be noted that the only way our our body gets it’s dose of tryptophan is through our diet - it does not produce tryptophan naturally; bananas is one of the easiest ways to get it (references: Nutritiondata.com, Chemistry Daily, Stanford Linear Accelerator Center, NIH MedLinePlus).
- Bananas are good for your blood: Bananas are one of the highest sources of naturally available vitamin B6: Vitamin B6 plays an important role in converting tryptophan to serotonin (read #3 above), and also helps the body to make hemoglobin - a crucial ingredient of your blood. Vitamin B6 is also essential for antibody production and to maintain a healthy immune response. It also helps to convert carbohydrates to glucose and thereby maintains proper blood sugar levels. A medium banana can take care of 1/5th of your daily recommended intake of vitamin B6 and is one of the easiest (and cheapest) ways to increase your dietary intake of the vitamin (references: NIH Office of Dietary Supplements).
- Bananas are good for kids: Let me quote this from NIH’s Medical Encyclopedia -
Bananas are part of the BRAT diet, a diet many physicians and nurses recommend for children recovering from gastrointestinal problems, particularly diarrhea. BRAT stands for the different components that make up the diet: Bananas, Rice cereal, Applesauce, Toast. These are binding foods that make the stools harder.
- Bananas are good source of dietary fiber: A single serving (one medium-sized banana) contains 16% of the daily recommended dietary fiber intake for a normal adult - that’s substantial for a single serving of any food. Fiber improves laxation (smooth bowel movements). Fiber-rich diets have also been linked to lower risk of coronary heart disease and of type 2 diabetes. Also, view this information in light of the following facts (references: Health.gov, NIH PubMed - abstract is sufficient):
Current recommendations suggest that adults consume 20-35 grams of dietary fiber per day. Children over age 2 should consume an amount equal to or greater than their age plus 5 grams per day. Yet the average American eats only 14-15 grams of dietary fiber a day. source: Harvard School of Public Health
Availability is the best part: Bananas are very affordable at about 35~40 cents per pound (on an average - in the US) and are generally available in almost all grocery stores; you don’t need to cook them or wash them (unless you want to eat the outer skin) and that makes them ideal as quick lunch substitutes. Consider bananas as an awesome and affordable dietary supplement.
Got sugar concerns?: People worry a lot about the carbohydrates (especially the sugar part) in bananas. To that end, here are a few quotes from a couple reliable sources:
A banana has a glycemic index of 52 and 24 grams of available carbohydrate. This gives a glycemic load of 12. In comparison, an apple having a glycemic index of 38 and 15 grams of available carbohydrate has a glycemic load of 6 … Although an apple may be a little better choice for a snack, eating a banana isn’t all that bad either because foods with glycemic loads in the low teens and below are the ones that should be selected as part of a balanced diet. (source: USDA.gov)
Despite being erroneously called “fattening” and too high in sugar, a small banana only contains about 100 calories, which is not much more than a medium apple. Nor should it raise your blood glucose level too high. (source: American Diabetes Association)
Like always, stuff should be done in moderation and it should be noted that all the above health benefits are “general observations” - and there must be, for sure, exceptions to general observations. If you have specific health conditions related to any nutritional constituents of bananas, make sure you consult your doctor before you go bananas on bananas.
If you have additional information (or even folklore ) about bananas, feel free to share it with us through your comments.