This sweet tropical fruit contains a whole host of healthful nutrients, all wrapped up in gut-healthy fibre.
Medically reviewed by Dr Roger Henderson and words by Annie Hayes
Readily available, portable, and bursting with fast-digesting energy, bananas are a fruit bowl staple across the globe. While they’re best known for having a high potassium content – one of the key minerals behind various banana benefits – this sweet tropical fruit contains a whole host of healthful nutrients, all wrapped up in gut-healthy fibre.
The humble banana is often overlooked in favour of more exotic (and expensive) fruit, despite being a bona-fide nutrient powerhouse.
To redress the balance and give the banana its moment in the spotlight, we asked nutritionist Rob Hobson, head of nutrition at Healthspan, to talk us through the many benefits of this bright yellow fruit:
12 science backed banana benefits
From supporting your heart health to fuelling your workouts, we’ve picked out 12 proven banana benefits.
- Bananas are highly nutritious
Bananas are mostly carbohydrates and water. The carbs in green, unripe bananas are mostly starch and resistant starch. As the banana ripens, the starch turns into glucose, fructose and sucrose. Bananas contain very little protein and fat.
The average (120 gram) banana contains 103 calories, 0.1g fat, 23.2g carbs, 20.7g total sugars, 1.7g fibre, and 1.4g protein. It also contains significant levels of micronutrients:
- Potassium: 396mg – 20 per cent of your Recommended Daily Allowance (RDA). ‘This mineral is required for proper muscle and nerve function as well as helping to lower blood pressure and easing fatigue,’ says Hobson.
- Magnesium: 32mg – 9 per cent of your RDA. ‘Required to build healthy bones and help the body to deal with stress,’ says Hobson. ‘Magnesium is also associated with healthy muscle and nerve function as well as helping the body to convert food into energy.’
- Thiamine (B1):18mg – 16 per cent of your RDA. ‘This vitamin is required for energy production in the body, digestion of carbohydrates and heart function,’ says Hobson.
- Vitamin B6:37mg – 27 per cent of your RDA. ‘Required for energy production in the body and as well as maintaining a healthy immune and nervous system,’ says Hobson.
- Folate (B9): 17 mcg – 8 per cent of your RDA. ‘Prevents neural tube defects in unborn babies and is essential for a healthy immune system and preventing anaemia,’ says Hobson.
- Vitamin C:11mg – 14 per cent of your RDA. ‘An antioxidant that helps to reduce the damage caused by excess free radicals in the body,’ says Hobson. ‘Vitamin C is also essential for healthy skin, wound healing and immunity.’
- Bananas improve digestive health
Bananas are high in fibre, which is essential for a healthy digestive system. The two main types of fibre found in bananas – pectin and resistant starch – are what’s known as soluble fibre, which acts as a prebiotic in the body. Unable to be digested, soluble fibre passes through the gut ‘where it’s fermented by bacteria,’ says Hobson. ‘It forms a short chain fatty acid called butyrate, which acts as an energy source for colonocytes – cells of the colon – and is involved in the maintenance of colonic mucosal health.’
The two main types of fibre found in bananas – pectin and resistant starch – are what’s known as soluble fibre, which acts as a prebiotic in the body.
- Bananas moderate blood sugar levels
Both pectin and resistant starch slow the emptying of your stomach, which in turn slows the release of sugar in the body,’ says Hobson. Additionally, bananas rank low to medium on the glycemic index (GI), which measures how quickly a food raises your blood sugar levels. This means that bananas are unlikely to spike the blood sugar of healthy people.
- Bananas are satiating
If weight loss is your goal, eating a banana can reduce your appetite and help keep you feeling fuller for longer. Again, this is due to the fibre content. ‘Foods high in fibre help to bulk out the diet, which can increase satiety,’ says Hobson. ‘Bananas are a good source of fibre, in the form of pectin and resistant starch. Research has shown that both of these fibres help to reduce appetite and increase fullness after eating.’
- Bananas protect heart health
Bananas are high in potassium and magnesium, which are essential for heart health. The potassium in bananas helps your kidneys to flush out excess salt, ‘easing tension in your blood vessels and reducing pressure,’ says Hobson. A large review of the existing research found that consuming between 1.3 and 1.4g of potassium daily is associated with a 26 per cent lower risk of heart disease. And that’s not all. The high fibre content of bananas ‘has been shown to help reduce the risk factors associated with heart disease such as high cholesterol and type 2 diabetes,’ he says. ‘Bananas also contain antioxidant flavonoids, which help to reduce inflammation in the body.’
- Bananas are a concentrated energy source
Bananas are a great way to get an energy boost during the day, says Hobson. ‘They contain a concentrated source of energy in the form of fruit sugars, which are released slowly as a result of the fibre,’ he says. And while providing a concentrated energy hit, a large banana contains around 100 calories, which is just a small percentage of your daily intake.
- Bananas can improve insulin sensitivity
Insulin sensitivity refers to how sensitive your cells are in response to the release of insulin. It’s important, because when your cells stop responding, this causes higher insulin and blood sugar levels, potentially leading to type 2 diabetes. Bananas are beneficial for insulin sensitivity due to their resistant starches. ‘Unripe bananas are high in these – the greener the banana, the more resistant starch it contains,’ says Hobson. ‘Research has suggested that consuming 15 to 30g of resistant starch a day could improve sensitivity to insulin by 33 to 50 per cent within four weeks. Of course, this doesn’t negate the need to also follow a healthy balanced diet and lifestyle.’
- Bananas support kidney health
Potassium is essential for maintaining fluid balance in the body and blood pressure control. For this reason, getting enough is essential to keep your kidneys healthy. With 20 per cent of your RDA in one serving, bananas are one of the richest sources of dietary potassium out there. ‘High blood pressure can put a strain on the kidneys, which may impact on its ability to function properly,’ says Hobson. ‘One study suggested that people who eat bananas up to six times per week were 50 per cent less likely to develop kidney disease than those who didn’t eat this fruit.’
With 20 per cent of your RDA in one serving, bananas are one of the richest sources of dietary potassium out there.
- Bananas fuel workouts
Forget expensive energy gels and sugar-loaded drinks – bananas are as beneficial as sports drinks for fuelling endurance exercise. In a study by Appalachian State University, trained cyclists downed either a cup of carbohydrate drink or half a banana every 15 minutes during a 46-mile simulated road race lasting up to three hours, and had their blood analysed before and after. Not only was the performance the same, but there were additional advantages to consuming the bananas due to their antioxidant, vitamin and mineral content, the study showed. Bananas also have a healthier blend of sugars than sports drinks.
- Bananas reduce muscle soreness
Muscle cramping and soreness is common, especially after exercising. ‘Cramping is not fully understood, but it’s thought to be the result of dehydration and electrolyte imbalances,’ says Hobson. ‘Bananas contain potassium and magnesium, which both act as electrolytes in the body.’ While the research linking bananas to easing cramps is mixed, some studies conclude that they are helpful for preventing the condition.
- Bananas are versatile
Bananas are a great on-the-go snack, but they also make a great sugar substitute in baking, and a nutritious addition to plant-based patties and fritters. ‘Bananas can also be used as an ingredient in many recipes, which include home bakes and even savoury foods such as curry,’ says Hobson. ‘You can also make a great vegan ice cream by simply blitzing frozen ripe bananas in a blender. Try adding unsweetened cocoa powder for a chocolate banana flavour.’
- Bananas are convenient
Bananas are incredibly easy to add to your diet, because they’re portable and don’t spoil quickly . ‘They are the perfect snack to carry around, as they come ready packaged in their natural skin,’ says Hobson. And thanks to their thick peel, bananas rarely contain high levels of pesticides or pollutants.