Have you ever eaten a banana that wasn’t quite ripe, either a little green at the stem or maybe too firm, and felt sick afterwards? Maybe you had a stomach ache, nausea or felt bloated and started burping uncontrollably. Or it could have been that you had diarrhea a few hours afterwards or felt your stomach turned upside down. It’s actually not that uncommon to experience gastrointestinal side effects after eating unripe fruit, especially bananas. Some people are more sensitive than others to the changes in nutritional status of unripe fruit compared to ripe fruit and may experience stomach upset for up to a couple of days after. Not to mention that existing gastrointestinal conditions like gastritis or irritable bowel syndrome can be made even worse if you eat unripe bananas and other green fruit.
Are unripe bananas bad for you? For the most part, any unripe fruit, including bananas, is bad for you. Usually, the more unripe the fruit and the more of it you eat, the more severe the side effects. Infelicitous food combinations such as unripe banana and soda or unripe banana and sour milk or unripe banana and coffee can make the side effects even worse. Eating unripe bananas at night, before going to bed or on an empty stomach can cause severe acid reflux and heartburn. And some people being more sensitive than others, they can be bothered by even slightly unripe or still under-ripe bananas. But the most at risk for side effects are people with existing gastrointestinal conditions which are more the most likely to experience side effects after eating unripe fruit in general.
Unripe bananas side effects include: acid reflux and heartburn, nausea, rarely vomiting sensation, general stomach upset, moderate to severe bloating, burping, stomach cramps, diarrhea, malaise from the stomach upset and worsening of existing digestive conditions such as gastroesophageal reflux, gastritis, irritable bowel syndrome and others.
Bananas that are green all over, mostly green with traces of yellow, more green than yellow, even more yellow than green and yellow all over, but with green stems can be considered unripe and best left to ripen further. Perfectly ripe bananas should be yellow all over, even at the stem, and preferably a uniform, golden yellow. Bananas with tiny brown spots are also usually ripe and good to eat.
1) Unripe bananas and stomach upset. Unripe bananas are considered insoluble fiber in the sense that the fiber they contain is highly resistant to digestion in the stomach compared to the fiber in the ripe fruit. You can tell this by the firmness of the fruit: the pulp of unripe bananas is visibly firm and starchy, whilst the pulp of the ripe fruit is soft and sweet. The greener, more unripe the banana, the more effort the stomach will put into digesting it, possibly resulting in indigestion and stomach upset. It’s also not uncommon for unripe fruit to cause nausea and, rarely, vomiting sensation, symptoms that accompany more severe indigestion. If you do happen to eat an unripe banana and it gives you indigestion, it’s better to wait 2-4 hours before eating anything else (or until you’re extremely hungry). Allow the stomach plenty of time to recover and, when you’re feeling better, eat foods that are easy to digest and only small amounts of food. Also read about the 7 Side Effects of Eating Unripe, Green Fruit.
2) Unripe bananas and heartburn. When your stomach is making an unusual effort to digest something, it produces more gastric juices to help break down the resistant food as best as possible so the nutrients in it can be extracted later on in the intestinal tract. But all green, unripe fruit, bananas included, contain resistant starches which are essentially more resistant to digestion. What this means is they require more time and effort to be digested. This also means that the stomach is likely to produce more gastric juices in an attempt to break down the unripe fruit. At the same time, more gastric juices also means more pressure on the esophagus muscles that keep stomach contents in and a higher chance they escape and rise into the lower part of the esophagus, causing heartburn.
3) Unripe bananas and acid reflux. When you eat foods that are hard to digest, the stomach has to put in more effort to break those foods down and usually produces more stomach acid. So when you eat unripe bananas, more than the usual amount of stomach acid will be produced to help digest them. The more you eat, the higher the stomach acid production. And the fuller the stomach with both food and gastric juices, the higher the likelihood of stomach contents escaping into the esophagus and causing acid reflux. If you are particularly sensitive to unripe fruits, have a history of acid reflux or simply eat too many unripe bananas (and fill up on food), you could experience more severe acid reflux, with stomach contents and especially gastric juices rising up as far as the back of the throat. Read more about what Foods to Eat and to Avoid for Acid Reflux.
4) Unripe bananas and gastritis. Because they contain resistant starches that are more difficult to digest and work up the stomach in the process, triggering excess stomach acid production, green bananas are not a good food to eat for gastritis. They are worst eaten on an empty stomach or in large amounts, but can worsen gastritis symptoms even when consumed in small amounts occasionally. Read more about what Foods to Eat and to Avoid for Gastritis. At most, gastritis sufferers may eat perfectly ripe bananas (golden all over, with tiny brown spots and soft pulp) occasionally.
5) Unripe bananas, bloating and burping. The resistant starch in unripe bananas is a source of food for bacteria in the gastrointestinal tract which ferment it and feed on it. But the fermentation process also produces air which results in gas, bloating and burping. Because of their high resistant starch content, unripe bananas can cause moderate to severe gas, bloating and burping, depending on how many you eat. The air can also lead to stomach cramps and general discomfort. People with irritable bowel syndrome may be more likely to experience side effects after eating unripe bananas and other fruit.
6) Unripe bananas and diarrhea. The more unripe the banana, the more resistant starch it contains. And resistant starch produces an effect similar to soluble fiber in the intestinal tract, meaning it has a laxative effect. This is why many people experience diarrhea after eating unripe bananas. The more unripe fruit you eat at once or the less tolerant you are to the starches, the more likely you are to get diarrhea.
Are unripe bananas toxic? Some people assume that the diarrhea is a sign the fruit are toxic. Unripe bananas are not toxic. They are just likely to upset the stomach because they are harder to digest when unripe and the starch they contain may produce a laxative effect in some people.
Unripe bananas and constipation. There is really not much concern that unripe bananas cause constipation. It’s true that the fiber in unripe fruit is different from that in ripe fruit and while unripe bananas contain resistant starches, ripe ones contain more sugar and pectin. And while the resistant starch in the unripe bananas relieves constipation by feeding good gut bacteria that regulate transit and exerting a slight laxative effect, the pectin in ripe bananas also softens stools to promote soft, easy bowel movements. So there should little risk of constipation from unripe bananas.
Except for the fact that the unripe fruit contains tannins, naturally occurring compounds that give you a dry mouth sensation or make your mouth pucker. Tannins may exert a mild astringent effect which can potentially lead to constipation if you eat too many unripe bananas at once, in successive days or are simply more sensitive to their astringent effects.
What is interesting with unripe bananas is that the side effects of eating them only occur when they are consumed raw. If you cook unripe bananas, the cooking will make the fiber more easily digestible and significantly reduce or completely eliminate the side effects, depending on the situation. The best unripe banana recipes are those that allow the fruit plenty of time to be cooked. Stewing with different vegetables is a great way to incorporate the green fruit into your diet. Read more about the Side Effects of Eating Bananas during all ripening stages.
Unripe bananas benefits. Are unripe bananas good for you? For the most part, no, they are not healthy for you because they cause side effects such as bloating, burping, heartburn, acid reflux, nausea and diarrhea. But the same element that accounts for these side effects (starch) also contributes to one major health benefit: prebiotic properties. Unripe bananas feed the good gut bacteria in the intestinal tract and help maintain healthy gut bacteria populations which, in turn, assist gastrointestinal health and contribute to nutrient production and absorption, better immunity and overall better health. Depending on how well you tolerate the green fruit, you may tell if, in your situation, eating unripe bananas is bad for you or good.