What a Banana’s Color and Spots Reveal

Jun 27, 2025 - 09:59 Updated: Jun 26, 2025 - 17:15

Bananas are incredibly popular and are officially the most eaten fruit worldwide. But which banana is better for us—one that is still green, a ripe one, or one that’s beginning to turn brown? While naturally rich in essential nutrients, their health benefits can vary depending on how ripe they are. Understanding the differences can help you choose the type of banana that is right for you: green, yellow, or yellow with brown spots.

“We all know that bananas ripen over time, but the actual process is fascinating.” Rachel Gargano, chief registered dietitian at Live it Up, told The Epoch Times via email. “Ripening is genetically programmed and includes biochemical and physiological changes, which result in the transformation in taste, texture, and smell that we’re so familiar with.”

Bananas are a fantastic source of vitamins and minerals, essential for maintaining good health. The vitamins and nutrients in bananas remain relatively consistent throughout the ripening process. What does change, however, is their antioxidant, starch, and sugar contents, which have different effects on blood sugar and the digestive system.

Illustration by The Epoch Times, Shutterstock

Green Banana (Unripe)

Eating starchy and not very sweet green bananas may seem unappealing. However, they feature in the cuisines of many cultures, such as those in the Caribbean, Central and South America, Africa, and India. Green bananas are generally cooked before eaten and used more like a vegetable than a fruit—although botanically speaking—bananas are considered berries. Green bananas can be prepared in various ways, including boiling, baking, frying, steaming, or roasting.

Sugar Content

“During ripening, some of the starch and fiber in the banana is broken down into smaller sugar molecules by naturally occurring enzymes, such as amylase and invertase,” said Gargano. Amylase breaks down starch into simple sugars, and invertase converts sucrose, a complex sugar, into fructose and glucose, which are simpler sugars.

Gargano said that the breakdown of starch and fiber into sugars is why the banana is softer, as it has less structure, and is also why it becomes sweeter as it ripens. An underripe banana has a higher fiber and starch content and less simple sugars than an overly ripe one.

“But it’s important to note that no matter the ripeness, the banana will maintain the same amount of carbohydrates throughout its lifecycle; the difference is just where those carbs are coming from, starch or sugar,” Gargano said.

Green bananas are rich in pectin and resistant starch. As bananas ripen, the pectin and resistant starch decrease, and starch converts into sugars, which you can see as the skin turns yellow and generally makes them easier to digest, softer, and sweeter.

Digestion

All bananas have pectin and resistant starch, types of fiber that benefit digestion.

Pectin is a soluble fiber that slows digestion and gives the gut more time to absorb nutrients. Soluble fiber also helps normalize bowel movements, making it helpful for both constipation and diarrhea while promoting satiety and helping you feel full longer.

“Due to the high fiber intake, an unripe banana is going to be most beneficial for digestion,” Courtney Pelitera, a registered dietitian with Top Nutrition Coaching, told The Epoch Times in an email. “It is going to help promote regular bowel movements and improve the gut microbiome.”

Microbiome

Resistant starch—especially abundant in green bananas—is not digested in the small intestine. When it reaches the large intestine, it ferments, providing food for beneficial gut bacteria and contributing to a healthy microbiome, the body’s bacterial populations essential for health.

Research has shown that bananas’ ample prebiotic fiber can positively affect gut microbiota. A 2024 Japanese study of 26 healthy women who ate two bananas daily for two weeks found a significant reduction in urinary indoxyl sulfate, a marker of microbiome health.

The resistant starch in green bananas can also help manage blood sugar and aid in weight loss. In a 2019 randomized controlled trial published in the British Journal of Nutrition, 113 adults with either pre-diabetes or Type 2 diabetes added green banana pulp to their diet in addition to their routine treatment. After 24 weeks, the group that took the green banana biomass showed lowered blood sugar and HbA1c, reduced blood pressure, and decreased body mass index.

The extra fiber in green bananas contributes to a lower glycemic index, Gargano said, which means they are digested and absorbed more slowly, resulting in a gradual release of glucose into the bloodstream.

If you are looking to improve your digestion and gut health, green bananas are a great choice, she added. The body does not digest its resistant starch—instead, it nourishes good gut bacteria, creating short-chain fatty acids. These byproducts help keep your gut lining strong and your intestinal cells healthy.

“And as we’re learning, a healthy microbiome not only helps with digestion but also immune function and our mental health. I definitely go for slightly green bananas whenever I can!”

Yellow Banana (Ripe)

There are situations where a ripe banana might be a better choice.

“A ripe or overripe banana might be more beneficial for those trying to improve their healthy carbohydrate intake, such as active exercisers, needing to eat before a workout. These are also great in smoothies or baked goods because they will have a stronger flavor,” Pelitera said.

When bananas are ripe or even slightly overripe, Gargano said, they contain fewer fructans, a fermentable carbohydrate that some people find difficult to digest. Fructans are FODMAPs—fermentable oligosaccharides, disaccharides, monosaccharides, and polyols—types of carbohydrates that are poorly absorbed in the small intestine and thought to contribute to symptoms such as bloating, gas, cramping, constipation, and diarrhea in some people.

Ripe bananas are also easier to digest as their resistant starch is converted into simple sugars. However, their higher sugar content means they have a more pronounced effect on blood sugar, so those with diabetes should be careful to eat ripe bananas in moderation.

Ripe bananas also contain more antioxidants than their unripe counterparts, meaning this stage can increase your intake of those helpful compounds and protect your body from damage due to free radicals.

Research on banana peels has shown that their antioxidants increase as they ripen, peaking at particular stages of ripeness before declining in overripe stages. Although eating banana peels may seem unappetizing, they are used in dishes like curries and stir-fries in some cultures’ cuisines, such as those in India and Southeast Asia. Vegan recipes even use banana peels for a bacon-like dish.

Yellow Banana With Brown Spots (Overripe)

Just because a banana has brown spots doesn’t mean it’s not good to eat. Slightly overripe bananas are full of nutrients. At this stage, the banana’s starches continue to break down into sugars, making them more easily absorbed and used by the body. For this reason, a slightly overripe banana is an excellent option for those with sensitive digestive systems or when you are feeling under the weather, and it may be challenging to keep food down.

Bananas are part of the BRAT diet—bananas, rice, applesauce, and toast. This diet is typically prescribed to those, especially children, with diarrhea, vomiting, or nausea, or when they are recovering from a digestive-related illness. The BRAT foods are gentle on the stomach and easy to digest, and in cases of diarrhea, they help the stool become more solid.

A banana, however, can be too ripe, and you shouldn’t eat a spoiled banana. Below are some ways to tell if it is too ripe to eat:

The peel is primarily black
The flesh is heavily bruised
The banana has liquified and is oozing out of the peel
There is mold anywhere on the banana

Your nose is also a good indicator, so don’t eat a banana that has a rotten or fermented smell.

Ultimately, if you are not choosing your banana based on a health condition or specific benefit, then how ripe it is comes down to personal taste preference. The good news is that your health will benefit, regardless of the banana you select.