Bananas are incredibly tasty and easy to eat.
What's more, they're rich in many essential vitamins and minerals.
Most people eat bananas when they're yellow and ripe, but green and unripe bananas are also safe to eat.
However, some people dislike their taste and texture.
Bananas are typically harvested while they're still green. This helps ensure they don't get too ripe before you buy them.
Therefore, you might see them in this color in the supermarket.
Besides being different in color, green and yellow bananas differ in several ways:
- Taste: Green bananas are less sweet. They're actually quite bitter in taste.
- Texture: Green bananas are firmer than yellow bananas. Their texture has sometimes been described as waxy.
- Composition: Green bananas are higher in starches. As bananas ripen and turn yellow, the starches transform into sugars.
Additionally, green bananas are harder to peel, while ripe bananas are easy to peel.
Bottom Line: Green and yellow bananas differ in taste and texture. Green bananas are also higher in starches.
Unripe bananas contain mostly starch, which makes up 70–80% of their dry weight (1).
Much of that starch is resistant starch, which is not digested in the small intestine.
Therefore, it's often classified as dietary fiber.
However, bananas lose their starch as they ripen. During ripening, their starch is converted into simple sugars (sucrose, glucose and fructose).
Interestingly, ripe bananas contain only 1% starch.
Green bananas are also a good source of pectin. This type of dietary fiber is found in fruits and helps them keep their structural form. Pectin breaks down when a banana becomes overripe, which causes the fruit to become soft and mushy (2, 3).
The resistant starch and pectin in green bananas can provide a number of health benefits, including improved blood sugar control and better digestive health ().
Bottom Line: Green bananas contain a high amount of resistant starch and pectin, which have been linked to several health benefits. As bananas ripen, most of the starches are turned into sugar.
Green and yellow bananas are both good sources of many important nutrients.
Although the exact nutrient profile of green bananas is not available, they should contain the same micronutrients as when they are ripe.
A green or yellow medium-sized banana (118 grams) contains (5):
- Fiber: 3.1 grams
- Potassium: 12% of the RDI
- Vitamin B6: 20% of the RDI
- Vitamin C: 17% of the RDI
- Magnesium: 8% of the RDI
- Copper: 5% of the RDI
- Manganese: 15% of the RDI
This is coming with around 105 calories, of which more than 90% come from carbs. Additionally, bananas are very low in fat and protein.
For more about the nutrients in bananas, read this article.
Bottom Line: Green and yellow bananas are high in many nutrients, including potassium, vitamin B6 and vitamin C. They consist almost entirely of carbs but contain very little protein and fat.
Green bananas are very filling, largely because of their high fiber content.
Fiber-rich foods provide bulk and promote satiety ().
Both resistant starch and pectin — the types of fiber found in green bananas — have been linked to an increased feeling of fullness after meals (, , ).
These types of fiber may also slow down the emptying of your stomach and make you eat less food (, ).
In turn, this may help you eat fewer calories, which could help with weight loss.
Bottom Line: Green bananas may have an appetite-reducing effect due to their high content of fiber and resistant starch.
The nutrients in green bananas may also have a prebiotic effect.
Instead of being broken down in your intestine, resistant starch and pectin feed the friendly bacteria that reside in your gut.
The bacteria ferment these two types of fiber, producing butyrate and other beneficial short-chain fatty acids (, ).
Short-chain fatty acids may help with various digestive problems (, , ).
In addition, there is some evidence suggesting that they help protect against colon cancer (, ).
Bottom Line: Consuming green bananas can help keep your gut bacteria healthy. It can also increase the production of short-chain fatty acids, which are important for digestive health.
Having high blood sugar levels is a major health concern.
If left untreated over time, it may lead to type 2 diabetes and raise the risk of other serious health problems.
Both the pectin and resistant starch in green bananas may help control blood sugar after meals (, ).
Unripe, green bananas also rank low on the glycemic index, with a value of 30. Well-ripened bananas have a score of around 60.
The glycemic index measures how quickly foods raise blood sugar levels after eating ().
The scale runs from 0 to 100, and lower values are good for blood sugar control.
Bottom Line: The pectin and resistant starch in green bananas can help control your blood sugar levels, especially after meals.
Green bananas are generally considered to be healthy.
However, there have been some online reports of people experiencing discomfort after eating them.
This includes digestive symptoms like bloating, gas and constipation.
Additionally, you may want to be careful with green bananas if you're allergic to latex.
They contain proteins that are similar to the allergy-causing proteins in latex, which may cause reactions for people with a latex allergy. This condition is known as the latex-fruit syndrome ().
Bottom Line: Green bananas are considered healthy, although they may cause digestive problems in some people. People with a latex allergy may also experience issues when eating them.
Green bananas may provide some additional nutrients and benefits that yellow bananas do not.
They're rich in resistant starch and pectin, which are filling, improve digestive health and help lower blood sugar levels.
However, some people find that green bananas have a bitter taste and bad texture.
Interestingly, the resistant starch and pectin gradually decrease as the banana ripens, so bananas that are yellow with a hint of green should still contain small amounts.
For this reason, the banana doesn't have to be completely green for you to get at least some of these benefits.
More about bananas: