Are Bananas Safe for Diabetics? Benefits and Risks

Bananas are rich in vitamins and minerals, such as potassium and vitamin C, as well as fiber and antioxidants. However, like other fruits, bananas are naturally high in sugar. Sugar and carbohydrates increase blood glucose (sugar) levels faster than protein and fats. Some people with diabetes may limit or avoid these foods to prevent blood sugar spikes.

Diabetes is a chronic (long-lasting) condition that occurs when the body doesn’t make enough insulin—a hormone that regulates blood sugar—or the insulin doesn’t function properly. This causes higher blood sugar levels. Following a diabetic-friendly diet can help control blood glucose levels and prevent complications such as kidney, nerve, and eye damage.

People with diabetes can eat fruit, including bananas. Fruits contain sugar but also provide vitamins, minerals, and antioxidant compounds. Bananas are also a good source of fiber, which may help reduce their blood sugar effects.

Smaller portions is key. You can also pair fruits with a source of protein or fat, such as nuts or plain yogurt, to reduce the glucose spike.

American dietary guidelines recommend consuming 1 ½ to 2 cups of fruit for women and 2 to 2½ cups for men daily. One large banana is equivalent to 1 cup of fruit. If you’re counting carbohydrates, the below fruit portions contain about 15 grams of carbohydrates:

• Half of a banana
• One cup of berries
• A small fruit (about the size of a tennis ball) such as apple, orange, peach, or kiwi
• 12–15 grapes or cherries

Fruit Sugar vs. Refined Sugar

Fruit sugar and refined sugar are different in several ways.

First, whole fruit contains fiber as well as sugar. Some foods with refined sugar may contain fiber, but many foods high in refined sugar, such as baked goods and cereals, are low in fiber.

Second, your body metabolizes (processes) fruit sugar differently than refined sugar. Your body can metabolize fructose—the type of sugar found in fruits—without insulin. Fructose is mostly metabolized in the liver, where it is converted into glucose for energy. Some glucose is stored in the liver, but most is released into the bloodstream. Fruits increase blood glucose levels, but they do so more slowly than refined sugar.

Jams and jellies often contain added sugars. Fruit juices lack fiber and contain much more sugar than eating whole fruit.

Ripeness determines how bananas affect blood sugar levels. Unripe bananas contain much more fiber than ripe bananas. One study showed that, per 100-gram serving, unripe bananas contain 18 grams of fiber, ripe bananas contain 4-5 grams, and overripe bananas contain only 2 grams. Fructose, glucose, and total sugar content also increase as fruits ripen.

Portion size is also important. Eating two bananas affects blood glucose levels more than eating one banana.

How Fiber Affects Blood Sugar

Carbohydrates increase blood glucose levels more than protein and fats do. Carbohydrates paired with fiber, such as whole grains, legumes, fruits, and vegetables, affect blood sugar less.

Fiber plays a crucial role in blood glucose management. High fiber intake can improve blood sugar, insulin, and hA1c (a blood sugar marker) levels in people with diabetes. It is also linked to a lower risk of type 2 diabetes and its complications.

The fiber content of fruit influences how much that fruit increases blood glucose levels. Fruits with higher fiber tend to have a lower glycemic index (GI). A low-GI fruit doesn’t spike blood glucose levels as much as high-GI fruits do. Higher fiber and lower carbohydrate fruits include, but are not limited to:

• Unripe or slightly ripe banana
• Goji berry
• Guava
• Avocado
• Raspberry
• Blackberry
• Blackcurrant
• Date
• Raisin

How much banana you can eat depends on your individual caloric and nutritional needs. One large banana is equivalent to 1 cup of fruit. If you’re counting carbohydrates, one large banana (about 136 grams) adds about 31 grams of carbohydrates to your diet. Here are some ideas to reduce how much bananas affect blood sugar:

• Pair bananas with foods that contain protein and fat: Consuming fruits with a balanced meal, a protein source (such as yogurt), or a fat source (such as nuts) can support blood glucose management. One study showed that consuming moderate- and high-GI fruits after main meals can improve blood insulin and insulin function. Low-GI fruits also improved both insulin and insulin sensitivity, whether consumed before or after a meal.
• Choose slightly unripe bananas: Ripe and overripe bananas contain more sugar and less fiber than unripe or slightly unripe bananas.
• Be mindful of portion size: Consuming a portion of a banana will increase blood sugar levels less than consuming one large or multiple bananas. You can eat half a banana at breakfast and put the rest in the fridge for an afternoon snack. Try to spread your fruit consumption throughout the day.

Identical meals can have varying effects on blood sugar levels in different individuals. So, your body may have a different glucose response to bananas than someone else.

The glycemic index offers a general idea of a food’s blood sugar effects, but it does not account for individual responses to foods. You can consult your healthcare provider for a diet personalized to your responses and nutritional needs.

People with diabetes can eat bananas and other fruits. Fruits are an important part of a balanced diet because they contain fiber, vitamins, minerals, and antioxidant compounds.

Bananas are high in fiber, which may help reduce their effects on blood sugar. You can eat smaller portions of bananas or pair the fruit with a protein or fat to reduce a blood sugar spike.