In this article:
- Bananas belong to the Musaceae family.
- This popular fruit originated in Southeast Asia.
- Bananas are technically a berry and can vary in color from yellow and green to purple.
- Bananas do not need to be attached to the plant to ripen. They are often picked and shipped while still green.
- Bananas grow in “hands,” because of their finger-like appearance, and make up a “bunch,” or the larger stalk.
- This fruit is a powerhouse of nutrients and may be beneficial for many health conditions.
Hanging a banana on a hook exposes the cluster of bananas to an even and consistent amount of oxygen, allowing them to ripen gradually and evenly without pressure. If you lay them on a bowl, bruising occurs, or moisture collects on the spot that is left sitting.
Bananas do not contain pesticides because their peels are strong, thick, and protective. The flour or meal of green bananas is 50% resistant starch, which acts like fiber and is not entirely digested.
Bananas are curved in shape. They have a firm, creamy flesh that is wrapped in a thick peel. They grow in large clusters of 50 to 150, with 10 to 25 individual bananas found in bunches, or “hands.”
Banana plants grow to be anywhere between 10 and 26 feet tall. There are two species of bananas:
- Sweet bananas (Musa sapient, Musa nana)
- Plantain bananas (Musa paradisiaca)
While plantain bananas are uniform in shape and size, sweet bananas have a variety of sizes and colors.
Bananas can have skins that are red, purple, brown, yellow, or green. Yellow bananas are the most commonly found in markets, and they turn brown or black when overly ripe.
Nutritional Content of Bananas
A very popular fruit, bananas are packed with vitamins, minerals, and other beneficial phenols. (1) A medium banana has 105 calories, 1 g of protein, no fat, and 27 g of carbohydrates, of which 3 g is fiber.
One banana also contains 12% (422 mg) of your daily needs of potassium, 3% (26 mg) of your daily phosphorus needs, 6% (10 mg) of your daily requirements of vitamin C, and 6% (24 mcg) of your daily folate needs. (2)
Health Benefits of Bananas
Given all the nutrients found in this yellow fruit, it is no wonder that it has many benefits for your health.
1. Keeps Bowel Movement Regular
Bananas contain 3 g of fiber, of which about half is insoluble fiber (1.2 g). Insoluble fiber aids in softening the stools, as well as trapping waste products to be taken out of the body.
One study of almost 3,000 young children with diarrhea found that the group given cooked green banana had much higher rates of recovery by days 10 and 14. Other studies found that green banana was beneficial in children with diarrhea. (3)(4)
Generally, bananas can replenish nutrients and contain electrolytes, particularly potassium. This makes them helpful for those suffering from diarrhea.
Another study found that eating a banana daily may improve bloating symptoms and is generally well-tolerated. (5)
However, excessive banana consumption can lead to constipation, especially if taken without enough water. Unripe bananas may lead to gas, bloating, and constipation.
Unripe bananas contain 100-250 mg of tannins and a lot of amylase-resistant starch. Saliva does not break down this type of starch very effectively. Hence, the overconsumption of unripe bananas may lead to constipation. (6)
Bananas can promote bowel regularity and may replenish nutrient stores after a bout of diarrhea. Excessive banana intake can lead to constipation.
2. Helps Control Blood Sugar
Bananas contain resistant starch, which is often fermented in the large intestine and acts a lot like fiber.
Resistant starch has been shown to reduce blood sugar, delay the emptying of the stomach, and improve insulin sensitivity. In these ways, bananas, particularly green bananas, may help with the management of diabetes. (8)(9)
Bananas contain components that may be beneficial for type 2 diabetes, but more research is needed.
3. Serves as a Natural Energy Source
As bananas contain carbohydrates, vitamins, and minerals, they are excellent sources of energy. These fruits contain complex and simple carbohydrates, which provide both short-term and long-term energy.
A study done in 2012 compared bananas and a carbohydrate beverage in their ability to refuel athletes. While both groups had similar performance time, blood sugar levels, and immune responses, the banana group had a better antioxidant capacity and lower oxidative stress. (10)
Bananas are good sources of simple and complex carbohydrates, as well as other beneficial compounds, which make this fruit a good source of energy.
4. Protects Against Stomach Ulcers
Bananas may protect the stomach by aiding the production of the stomach’s protective lining, which serves as a layer against stomach acid.
The fruit also contains compounds called protease inhibitors, which may kill bacteria in the stomach, including the bacteria that cause ulcers.
In one study, unripe plantains that were dried and powdered were investigated as possible antiulcer drugs. Results showed that an extract of these bananas might help treat ulcers, but more research is needed. (11)
Bananas contain compounds that may help with stomach ulcers, but more research is needed to understand the proper usage and dosage.
5. Beneficial for Celiac Disease
Celiac disease is an immune-mediated disorder marked by a total intolerance to gluten, and affected individuals must follow a strict diet that avoids all gluten products.
Flour made from banana peels has a higher nutrient content with more minerals, fibers, phenolics, antioxidants and, therefore, may be a healthy alternative to other gluten-free products. (13)
Banana flour can then be utilized as a substitute in various dishes, including gluten-free meals. Scientific evidence supports the use of bananas in widening the food choices for patients having celiac disease. Moreover, additional research can help elucidate its benefits.
6. Helps with Heart Health
Bananas are a good source of potassium, a mineral that is essential in heart health.
Potassium helps the heart maintain a regular beat and also works as an electrolyte to regulate the water in the body.
Individuals eating a diet high in potassium may regulate their blood pressure and reduce their risk of stroke. (22)
The World Health Organization (WHO) recommends a potassium intake of 3510 mg/day to lower blood pressure and decrease the risk of cardiovascular disease. (7) One medium banana contains 422 mg of potassium.
Bananas are a good source of potassium, which can help lower blood pressure and regulate electrolytes. This reduces the risk of stroke and other cardiovascular diseases.
Types of Bananas
The common varieties of bananas are:
- Banana (Cavendish): This classic banana is mildly sweet when ripe and has green or yellow skin. As the banana continues to ripen, it turns brown and then black. The flesh gets soft and brown and ferments. When buying, choose fruit without blemishes or bruises.
- Plantain (Green Banana): This banana is larger, is less sweet, and contains more starch. It is often used in cooking. When plantains are green, they have a neutral flavor and are firm and white.
Ripe bananas have a sweet taste, however, on further ripening, the skin may turn brown or black. They are often used in fried, boiled, or baked forms.
- Manzano: This fruit is often smaller and sweeter than the classic Cavendish banana. It has a typical banana flavor with a hint of apple.
- Red Banana: This banana is shorter and plumper and has a dark red peel. It is also creamy and a bit sweeter than Cavendish bananas.
- Burro Banana: This banana has a unique blocky shape. It is also shorter and thicker.
The most popular banana varieties found in markets in the United States are the Big Michael, Martinique, and Cavendish.
Plantains are commonly found in today’s markets as well, but due to their higher starch content, they are usually cooked. Plantains have more beta-carotene than sweet bananas.
Consuming and Storing Bananas
Bananas can be eaten both cooked and raw, and they are often processed into many food products. They can be pureed or blended to use in ice creams, yogurt, baked goods, and baby food.
Bananas can also be peeled, cut, then frozen to be used in smoothies or baked goods later. They can also be dehydrated or dried.
Plantains can be fried into chips and are a popular snack item. Whole plantains are also dried and then ground into flour.
Choose bananas that are green or yellow with no dark or brown spots. To slow the ripening process, store bananas away from other fruits, as these emit ethylene gas that speeds up ripening.
If you want to speed up the ripening process, place bananas in a paper bag or store them next to other fruits.
Safety of Bananas
While bananas are generally thought to be safe, banana allergies can occur. Allergic reactions can vary and include symptoms such as skin rashes, itching of the mouth and throat, swelling of the skin and mucosal linings, and even narrowing of the throat and wheezing.
Symptoms often occur within seconds or minutes of consuming a banana.
Banana allergies often occur along with allergies to other foods, as part of oral allergy syndrome, in which the allergy affects the mouth or throat. There are two types of oral allergy syndromes –pollen food syndrome and latex food allergy.
Those with a birch pollen allergy may develop symptoms up to 1 hour after eating a banana. Those with a latex allergy may also experience symptoms after consuming foods that contain latex, such as bananas.
ACE inhibitors help relax blood vessels and are taken for blood pressure. People taking ACE inhibitors, such as captopril, enalapril, and lisinopril, may experience an increase in potassium levels.
Too much potassium can cause irregular heartbeat and heart palpitations. If taking an ACE inhibitor, avoid eating too much potassium sources as this can cause high levels of potassium in the blood.
Diuretics are used to reduce fluid in the body and also to manage blood pressure. If taking a diuretic, avoid foods that are high in potassium, as these may interfere with the electrolyte and fluid balance in the body.
Always speak with your doctor or pharmacist if you have questions about consuming potassium-rich foods such as bananas while taking certain medications, particularly those for high blood pressure, including ACE inhibitors and diuretics.
Use of Banana Peels
The peels of bananas are also rich in potassium and may help keep teeth healthy, strong, and white. They are abundant in other minerals that may promote skin health.
Banana peels also have antibacterial properties. One study found that an extract of banana peel combated P. gingivalis and A. actinomycetemcomitans. (14) However, more studies are needed to establish the antibacterial property of banana peels.
Another study found that extract from an unripe banana peel had strong antioxidant activity and had a high phenolic content. (15)
Can everyone eat bananas?
Those with medical conditions that cause high potassium levels may want to avoid consuming too many bananas. Similarly, those taking ACE inhibitors and diuretics should avoid too much of this fruit.
People with diabetes can safely eat bananas in conjunction with a carbohydrate-balanced diet.
When is the best time to eat a banana?
As bananas ripen, their taste and nutritional content change. The less ripe a banana is, the less sweet it is due to the starches that have not yet broken down into sugars.
Otherwise, bananas can be consumed at any time of day. The potassium in bananas may help promote good sleep at night.
Do bananas affect weight?
Many people often avoid bananas when they are trying to lose weight because of the perception that they are high in carbohydrates. However, the resistant starches present in this fruit may lead to increased satiety.
Studies have shown that intake of resistant starch can produce a feeling of fullness for long periods, which can lead to better weight management. (16)
Despite bananas’ reputation as being bad for weight loss, there is no evidence that bananas lead to weight gain.
An analysis of three large studies found that people who ate more fruits and vegetables of all kinds had favorable outcomes with weight management. (17)
Do bananas boost mood?
Two studies found that eating raw whole fruits is linked to lower rates of depression, anxiety, and negative mood and an increase in perceived life satisfaction. Researchers do not yet understand the link, so more research is needed. (18)(19)
Can bananas help sleep?
Foods that contain tryptophan are known to help with sleep. Tryptophan is an amino acid that turns into serotonin and melatonin, two chemicals in the brain that promote healthy sleep. Magnesium, potassium, and calcium are also known to help calm and relax muscles. (20)
Can babies eat bananas?
Bananas are often among the first foods introduced to babies when they start solid foods. Bananas can easily be mashed into a puree and fed to infants as soon as the pediatrician allows the introduction of solid foods.
How many bananas can I eat in a day?
Current recommendations are for adults to consume at least 2 cups of fruit per day. This is equivalent to about two bananas. That said, a healthy diet includes a variety of fruits and vegetables, so mix up the fruits you eat daily.
Eating a dozen bananas per day may lead to excessively high levels of vitamins and minerals.
What happens if you eat too many bananas?
Bananas have no side effects when eaten in moderation. However, excessive consumption can lead to headaches, drowsiness, irregular heartbeat, and kidney issues.
People taking ACE inhibitors and diuretics, individuals with diabetes, and those with advanced chronic kidney disease should avoid eating too many bananas as this may have adverse side effects, such as a buildup of potassium in the body. (21)
Here are some of the ways you can enjoy bananas.
1. Banana Pancakes
- 1/2 cup all-purpose flour
- 1/2 cup oat or whole-wheat flour
- 2 tsp sugar
- 1 tsp baking powder
- 1/4 tsp salt
- 1 egg, beaten
- 1 cup milk of choice
- 2 tbsp vegetable oil or melted butter
- 2 ripe bananas, mashed
- In a bowl, whisk together the flours, sugar, baking powder, and salt. In another bowl, combine the egg, milk, oil or butter, and bananas and mix them well.
- Stir the dry mixture into the banana mixture. Mix to combine, but leave the batter slightly lumpy.
- Lightly oil a griddle or frying pan or spray with cooking spray. Heat over medium-high heat.
- Pour batter onto the pan to the desired size. Wait until the edges have set and look dry and bubbles appear on the top of the pancake. Flip. You may need to adjust the heat and turn it down.
- Cook until the pancakes are golden brown on both sides. Serve immediately.
2. Banana Breakfast Bars
- 2 medium bananas
- 1/4 cup coconut oil
- 1/4 cup brown sugar, packed
- 1 egg
- 1 tsp vanilla extract
- 1/2 tsp salt
- 1/2 tsp baking soda
- 1/2 cup whole-wheat flour
- 1 cup old-fashioned oatmeal
- Add-ins (optional): mini chocolate chips, peanut butter
- Preheat oven to 350°F.
- Grease an 8×8-inch pan or spray with cooking spray.
- In a large bowl, mash bananas. Stir in oil, brown sugar, egg, and vanilla extract. Mix until well combined.
- Stir in salt, baking soda, flour, and oats. Mix until combined, although some lumps will remain. If using optional add-ins, stir them in now — Spread mixture into the pan.
- Bake for 18-22 minutes until the edges are brown and the mixture is set.
- Allow to cool completely and then slice into bars.
3. Banana Soft Serve
- 2 bananas
- 1 tsp vanilla extract
- Optional: other frozen fruits
- Peel bananas and cut into chunks. Freeze.
- Place the frozen banana chunks and vanilla extract into a food processor. Add other fruits if using.
- Process until the banana is smooth. The mixture should be creamy and have some air whipped into it from the food processor.
- Serve immediately. You may garnish with syrup, chocolate chips, or your favorite ice cream toppings!
Bananas are a popular fruit around the world. Their sweet, creamy taste and convenient natural packaging make them a go-to pick for many. This fruit is enjoyed alone as a snack and in a variety of cooked and baked dishes.
They are rich in many nutrients, including potassium and fiber, which make them a healthy choice. These fruits contain compounds that may be beneficial for heart and digestive health.
Bananas also contain resistant starch, which may be beneficial for different health concerns. Diabetics and those trying to lose weight do not need to avoid this fruit, but bananas should be enjoyed in moderation.
Certain populations, such as those taking particular medications and those with kidney disease, should limit their banana intake.
Expert Answers (Q&A)
Answered by Alex Roberts MS, CD (Registered Dietician Nutritionist)
Bananas are portable and an easy low-calorie snack to take on the go. Eating a banana on an empty stomach may give you a temporary burst of energy but will likely leave you feeling sluggish, tired, and hungry a couple of hours later.
Bananas are made up mostly of sugar (fructose) and, when eaten alone, can cause hunger and an energy crash shortly after consumption.
When eating a banana, pair it with a protein source and healthy fat to help feel more satiated, have prolonged energy, and decrease your cravings and potential for overeating later in the day.
Some great options to pair with a banana include 1 tablespoon nut butter of choice, Greek yogurt, or 1 ounce of almonds.
Eating a single banana with a glass of milk has not been shown to cause weight gain. However, eating any food in excessive amounts can cause weight gain if eaten regularly.
It is best to avoid eating anything 2-3 hours before going to sleep. Metabolism slows down while sleeping, and a full stomach can make falling asleep more difficult and uncomfortable.
Bananas are carbohydrates, which become energy, and our body is not exactly looking for more energy when it is time for bed.
However, if you are looking for a snack a couple of hours prior to sleep, bananas may be a good option as they contain magnesium. This mineral has been shown to produce a calming effect, perfect for getting ready to wind down for the evening.
Bananas have commonly been used to treat digestive health issues, including diarrhea, as they are bland and easy to digest. Bananas are rich in potassium, an electrolyte lost with diarrhea, and can help replenish stores when eaten while experiencing diarrhea or vomiting.
Green or unripe bananas contain resistant starch, a type of carbohydrate that “resists” digestion in the small intestine and ends up in the large intestine. It is absorbed slowly and may support gut healing. (23)
Bananas are a great source of potassium, magnesium, and fiber, which have many health benefits.
Potassium is vital for heart and muscle health. It plays a role in sending signals for the heart to beat regularly and for the muscles to contract. Potassium also offsets the effects of excessive dietary sodium. An insufficient level of potassium and excess sodium can lead to high blood pressure. (24)
Bananas are a good source of fiber, which may benefit digestive health. Resistant starch, found in unripe bananas, escapes digestion and ends up in your large intestine, where it becomes food for the beneficial bacteria in your gut. (25)
Bananas are also a great choice when exercising. They are high in minerals that need to be replenished after a high-intensity or long-duration exercise and provide fuel for endurance activities. This fruit is also easily digestible.
Bananas are a popular fruit for its convenience, versatility, and sweet flavor profile. They are shown to aid in digestive and cardiovascular health. Remember to include protein and healthy fats when consuming bananas to prolong your energy and avoid overeating.
About Alex Roberts, MS, RDN, CD: Alex is a clinical dietitian at Virginia Mason Medical Center in Seattle, Washington. She provides medical nutrition therapy and education to patients in the critical care unit.
Outside of work, Alex enjoys spending time in the kitchen, exploring the outdoors, and providing nutrition and wellness information to her family and friends.