Green bananas are safe to eat and may carry real health benefits, according to a report by Verywell Health. Their high content of resistant starch can help keep blood sugar levels stable and support gut health.
Studies have linked eating green bananas, particularly in flour form, to reduced hunger and better feelings of fullness in healthy people. The fruit may also aid weight loss and improve insulin sensitivity in people with type 2 diabetes and obesity, and it may reduce inflammation in people who are overweight. Green bananas have also been used to treat chronic diarrhea and constipation in children.
Most of these benefits come from the fruit's high fiber and resistant starch content. Resistant starch functions much like fiber and supports gut health, according to an article on resistant starch consumption cited in the report.
As a banana ripens, its resistant starch converts into sugar, which is why unripe fruit contains far more of it. A 100-gram serving of unripe banana has roughly 14 grams more fiber and 9.3 grams more resistant starch than the same amount of ripe banana.
Lower sugar content in green bananas
Green bananas contain about 5 grams less sugar per 100 grams than ripe ones, according to an article on the fiber, starch and sugar content of bananas at different stages of ripeness cited in the report. Because of this and their higher fiber content, their glycemic index is also lower, at around 30 compared with 51 for ripe bananas.
The glycemic index measures how much a food raises blood sugar levels, a figure that matters especially for people with diabetes.
How to eat green bananas
Green bananas are firmer and less sweet than ripe ones, but different cultures eat them both raw and cooked. They can be thinly sliced and added to salads, boiled and mashed like potatoes, stirred into oatmeal, fried with spices and onion, or cooked in a pan.
Further research is still needed to determine whether the cooking method affects the fruit's beneficial properties.
Green banana flour
Many studies have focused specifically on the benefits of green banana flour, which is made from dried and ground unripe bananas. About 74% of the flour is resistant starch.
The food industry is also exploring the use of green bananas to produce powdered supplements and as a fat substitute in cooking.
Who should avoid green bananas
Green bananas are generally considered safe, but in some people they can cause stomach upset or constipation. This can happen from eating too much fiber or increasing fiber intake too quickly, according to a review of the health benefits of green bananas cited in the report. Because of this, green bananas should be added to the diet gradually.
People with a latex allergy should also avoid bananas because of latex-fruit syndrome. Latex and certain fruits contain similar proteins, so people allergic to latex sometimes react to bananas as well. Such a reaction occurs in roughly 30% to 50% of people with a latex allergy.
Experts have previously outlined warning signs to look for when buying bananas, noting that color alone cannot reveal when a banana has reached peak ripeness. Separate reporting has also covered how to store bananas properly to keep them from turning black, including removing them from a plastic bag as soon as they are bought.
