Are Bananas Good For Type 2 Diabetes?

In the United States, Type 2 diabetes is relatively common among older people (and occasionally among younger ones). Managing the condition is complex, and several factors must be considered, including diet.

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What is Type 2 diabetes?

Type 2 diabetes is when your cells stop reacting properly to insulin, a phenomenon called insulin resistance. This interferes with your cells' ability to remove sugar from the bloodstream, resulting in its increase in the blood. This also causes your pancreas to make more insulin, which can slowly damage your pancreas and reduce the amount of insulin produced in the long term. 

Your blood sugar also rises further, creating a vicious cycle that can eventually lead to complications such as high blood pressure, heart disease, strokes, and kidney failure. Elevated blood sugar affects your entire body, and poorly-managed diabetes is a life-threatening disease.

The go-to treatment for type 2 diabetes and prediabetes — when your blood sugar is elevated but not yet in the range for diabetes —  is lifestyle changes. Some of the most important changes are those related to diet. 

Lifestyle changes can prevent prediabetes from turning into diabetes and help keep people at high risk of developing the condition. It's vital for people with type 2 diabetes to eat a healthy diet and work with a nutritionist to ensure they eat the right foods to manage their blood sugar.

Doing so can reduce or postpone the need for medication and/or insulin, although many people with diabetes will still eventually need medication.

Some foods are known for being particularly good or bad for people with diabetes. One food that is often mentioned as being bad is bananas.

Are bananas safe for Type 2 diabetes?

While one may think of bananas as non-sweet fruit, a medium-sized banana has about 22 grams of carbohydrates. Because of this, it's often thought that bananas will contribute to spikes in blood sugar, and thus people with diabetes should avoid them.

The real picture is, of course, a lot more complex.

First of all, bananas are generally good for you. Bananas contain fiber, potassium, folate, antioxidants, and many other nutrients. This supports heart health, which is vital for people with diabetes. Also, diabetes often goes hand in hand with high blood pressure. Potassium, which bananas are particularly high in, helps keep blood pressure under control. 

Important note: If you are on potassium-sparing diuretics for high blood pressure, you may be told to limit potassium intake.

The American Diabetes Association recommends that people with diabetes consume fruit in moderation, including bananas. This doesn't mean you should ignore those carbohydrates, but you should consider how many carbs you need daily.

Bananas can easily be switched in for less healthy sources of carbohydrates, such as white bread. However, another factor in play is how ripe your bananas are. 

As bananas ripen, starch changes to free sugars. The amount of carbohydrates stays the same, but the form of those carbohydrates changes. 

Underripe bananas have a lower glycemic index, meaning it takes longer to release sugar into the bloodstream. This is due to its higher resistant starch content, a more complex carbohydrate that can’t be digested in the small intestine. In short, you should eat underripe bananas rather than ripe or overripe ones. 

Underripe bananas also make you feel fuller for longer. Buy green bananas in the store, use them fairly quickly, and resist the temptation to use the overripe ones to make banana bread. Instead, consider giving them to a friend who doesn't have diabetes. 

Many people would prefer not to eat unripe bananas, but you can make them much more palatable and fun by cooking them. In Jamaica, for example, people like to boil green bananas and serve them as a side with dumplings. If you have to wait for it to ripen, eat it as soon as it is ripe. 

Another alternative is plantains, a tasty variety of bananas popular in Central America, Africa, and the Philippines. Plantains are cooked in several ways and are traditionally eaten unripe. Some recipes can be made with either unripe bananas or plantains (be aware that some recipes that call for green bananas mean plantains).

Again, moderation is still key here, but bananas are not the horrible blood sugar spike inducer you may have heard about.

How many bananas can I eat?

Unless you have been asked to limit potassium, bananas are safe. You should check with your doctor. If you have been advised to reduce carbs in general, you will need to keep your banana consumption within your "carbohydrate budget."

You should also take into account the size of the banana. Buying smaller bananas, where possible, is a good idea to help keep your sugar down and practice disciplined portion control. Avoid banana milkshakes and smoothies, which tend to have more sugar. Avoid commercial banana chips, which often have added sugar. 

Later in the article, there's a link to make your own banana chips. Or you can check the ingredients and make sure there is no sugar or other hidden ingredients. Be particularly careful with flavored banana chips.

You should also spread out your fruit consumption. Have a banana or an apple, then have the other one later. Always pair your bananas with a healthy fat or protein source such as pistachios or walnuts. Nut butter works well with bananas as long as they have no added sugar.

When it comes to how many bananas you can eat daily, it also depends on how bananas specifically affect you. Unripe bananas are always going to be better. Some people may be sensitive to the effect of bananas on glucose. Otherwise, you might want to switch bananas for another fruit to increase potassium intake and support blood pressure control. Typically, most people should only eat one or two bananas a day.

A specific group¹ of people with diabetes should be careful about consuming bananas, and that is people who have poor kidney function. 

Elevated blood sugar can eventually cause progressive kidney damage. When your kidneys are not fully functional, they can't remove all the potassium from your blood, resulting in hyperkalemia,² which can cause serious heart problems and potentially be fatal. If you are taking beta-blocker medications for cardiovascular disease, you should also eat fewer bananas, as this class of medications raises potassium levels in the blood.

In general, most people with diabetes can eat one or two medium-sized bananas a day, keeping in mind what other fruit you are consuming.

Risks of overeating bananas

Eating too many bananas, especially overripe ones, can raise your blood sugar significantly. You should not eat an entire bunch of bananas at once. Bananas have also been associated with weight gain, which can contribute to the effects of diabetes. Diabetes can contribute to weight gain, and diabetic medications often have weight gain as a side effect, including insulin.

However, it is not true that eating too many bananas can cause hyperkalemia. Unless you have kidney disease or are taking medicine that affects potassium levels, the amount of potassium in bananas is normally not high enough to affect your potassium levels.

Unripe bananas can sometimes cause constipation, so be careful if you are prone to it. If you have constipation after eating a meal containing unripe bananas, be aware that they could be the culprit. For most people, however, this is not a concern.

However, the primary risk of eating too many bananas remains the same as with any source of carbohydrates and sugars — weight gain and/or reduced blood sugar management. Dietary imbalances can be caused by eating too much of any food, regardless of how healthy it is.

Health benefits of bananas

As already mentioned, bananas have great nutritional value and are overall a healthy fruit. Here are a few known health benefits of bananas:

Improved digestion

On top of the fiber content, unripe bananas contain resistant starch, which is prebiotic. This means that it makes it to your large intestine, where it helps feed beneficial bacteria in your gut. This also supports digestion. The fiber also helps you feel full longer, which can help you with portion control. Mixing bananas with protein makes this even better.

Improved heart health

The potassium, folate, antioxidants, and fiber in bananas support heart health. It is relevant to emphasize that high-fiber diets reduce your risk of cardiovascular disease, helping to compensate for the increased risk that comes with being diabetic.

Lower blood pressure

As already mentioned, potassium can help lower your blood pressure by reducing the stiffness of the arteries and veins that contributes to high blood pressure. Most people with diabetes develop high blood pressure eventually, and getting enough potassium can help stave off this complication.

Vitamin B6

Bananas are a great source of vitamin B6,³ which has been shown to reduce the risk of heart disease, stroke, and cancer. Many of the other good sources of B6 are animal products, so if you are aiming for a plant-based diet, it's worth remembering bananas are a good source.

Improved insulin sensitivity

People with a family history of diabetes should consider increasing their consumption of foods containing resistant starch. Resistant starch can also help your cells process insulin. Consuming more of it can help slow or even reverse the progression from prediabetes to diabetes.

Improved recovery after exercise

Eating a banana before your workout can have some of the same effects as drinking a sports drink.

Being a natural fruit, the specific nutrient composition of bananas varies, but bananas are a good source of:

  • Vitamin B6

  • Fiber

  • Magnesium

  • Potassium

  • Manganese

  • Vitamin C

These nutrient values are for the common Cavendish banana, the typical variety you will see in the supermarket. You can also find red bananas, which are rich in vitamins B6 and C. In fact, they have the above nutrients except for the manganese, and with the addition of phosphorus and calcium. They also have a distinctly different flavor. 

In other words, bananas are safe and often beneficial for people with diabetes as long as they are consumed in moderation. 

Diabetes-friendly snack ideas with bananas

Not everything you do with bananas is diabetes-friendly. But if you don't want to just reach for a banana or want something even better for you, then check out these snack ideas:

Peanut butter banana bites

Use natural peanut butter with no added sugar. Ideally, the only ingredients should be peanuts and salt. Some sugar-free peanut butter brands contain an artificial sweetener named xylitol, which is highly poisonous to dogs. Consider avoiding these brands if you own one. If you're allergic to peanut butter, you can use any kind of nut or seed butter. Making your own granola helps avoid sugar.

Home-made banana chips

Store-bought banana chips are often high in sugar, but you can make your own easily. Choose a baked recipe rather than a deep-fried one. If you have or know somebody with a dehydrator, that's another way to make banana chips that will last a long time.

Dipped bananas

Some of the ideas listed are not diabetes-friendly, but crushed walnuts, ginger, and cinnamon are great options. And it's very quick — just mix up your dip, peel your banana, and (double) dip away. You can experiment with flavor combinations until you find something that works for you.

Banana almond butter roll-ups

In making banana almond butter roll-ups, you need a whole wheat tortilla spread with almond butter (peanut butter works too), wrapped around a peeled banana. You can add in things like hemp or chia seeds. Or slice it up and pretend it's sushi. Rolling a peeled banana in nuts is also a good way to make "banana sushi."

Banana crackers

Make banana crackers with just bananas and oats, and serve with high protein or good fat spread. Oh, and they have the advantage of being a good gluten-free alternative if you use gluten-free oats. It’s handy if somebody has celiac disease, and you can put anything on them that you can put on regular crackers.

Banana oat bars

In making banana oat bars, use unsweetened applesauce, leaving off the chocolate chips or using sugar-free options. These make a good on-the-go breakfast that you can make on weekends when you have the time and enjoy all week or freeze for later.

Unripe bananas or plantains are best cooked and treated like root vegetables. Look to Caribbean cooking for great ideas on how to enjoy them. If you know how to make curry, you can put some unripe bananas in there, and also make sure to add turmeric — a spice full of great antioxidants.

From the recipes above, you will note that nut and seed butter are a great combination. They contain protein and good fats that combine well with bananas to fill you up without spiking your blood sugar.

However, avoid Nutella and generics as the first ingredient is sugar. Always check the ingredients on your nut butter.

Other ideas include chopping up bananas and putting them on a salad or with your breakfast cereal or low-fat/greek yogurt. Mashed bananas on toast make a good substitution for sugary jams and preserves. Of course, there's nothing wrong with just grabbing a banana out of the fruit bowl as a snack, but remember that it is better to combine it with protein.

Avoid anything made to "use up" overripe bananas, as they contain a lot of sugar. There are "healthy" banana bread options out there, but even those should be consumed only in moderation. While it might suck to have to throw away a speckled banana, overripe bananas can cause your blood sugar to spike.

The lowdown

It's a myth that bananas are bad for people with diabetes, although you should not consume too many. One or two a day is good, and consider your consumption of other fruits. Bananas will not cause a massive spike in blood sugar levels, besides containing many other nutrients that can protect your heart and aid digestion.

Unripe bananas are better than ripe bananas but generally have to be cooked to make them enjoyable. Avoid overripe bananas and desserts made with them as at that point, the beneficial resistant starch has been almost completely converted to free sugars.

Enjoy your bananas with good fats and protein for a filling snack. Talk to your dietitian to find out exactly how you should include bananas in a balanced, healthy diet to manage your diabetes better.

Have you considered clinical trials for Diabetes?

We make it easy for you to participate in a clinical trial for Diabetes, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

Joining community groups and exercise programs for my condition made me feel empowered – but I want to be part of finding a cure.
Peter, 64



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