Think bananas make every smoothie healthier? A gastroenterologist explains why he skips them

Smoothies have become a popular choice for people looking for a quick and nutritious meal or snack. Packed with fruits, vegetables, nuts, seeds and protein-rich ingredients, they are often seen as an easy way to increase nutrient intake. Among all smoothie ingredients, bananas are probably the most common. They add natural sweetness, create a creamy texture and blend well with almost any combination of fruits.

Because of these qualities, many people assume that adding a banana automatically makes a smoothie healthier. However, gastroenterologist Dr Saurabh Sethi recently shared a different perspective. In a social media video, he explained why he personally avoids adding bananas to his smoothies and highlighted three reasons behind his decision.

According to Dr Sethi, bananas may reduce certain antioxidant benefits in smoothies, increase the amount of simple carbohydrates when fully ripe and contribute extra calories. While this does not mean bananas are unhealthy, he believes people should understand how they interact with other ingredients before automatically adding them to every smoothie.

How bananas may affect nutrients in smoothies

One of Dr Sethi’s main concerns involves an enzyme naturally found in bananas called polyphenol oxidase. This enzyme plays a role in the browning process that occurs when bananas and some other fruits are exposed to air.

The gastroenterologist referred to research that examined how this enzyme may affect certain beneficial plant compounds known as polyphenols. Polyphenols are natural substances found in many fruits, vegetables and plant-based foods. They are particularly abundant in berries, cocoa, green powders and some leafy greens.

These compounds are valued because they have antioxidant properties. Antioxidants help protect the body from oxidative stress, a process that can damage cells over time. Many people intentionally add berries such as blueberries, strawberries and blackberries to smoothies because of their high polyphenol content.

According to Dr Sethi, when bananas are blended together with ingredients rich in polyphenols, the enzyme polyphenol oxidase may reduce the availability of some of these beneficial compounds.

This does not mean all nutrients are destroyed or that the smoothie becomes unhealthy. However, it suggests that combining bananas with certain antioxidant-rich ingredients could lower some of the benefits people are hoping to get from foods like berries.

The topic has attracted attention among nutrition experts because many smoothie recipes combine bananas and berries. While researchers continue to study the exact effects, Dr Sethi believes it is worth considering alternative ingredients if the primary goal is to maximize antioxidant intake.

For example, people who want to focus on polyphenol-rich smoothies may choose fruits such as mangoes, pineapples or avocados instead of bananas. These alternatives can still provide texture and flavor while potentially preserving more of the beneficial compounds from berries and greens.

The impact of ripe bananas on sugar and calories

The second reason Dr Sethi avoids bananas in smoothies relates to their carbohydrate content, particularly when they are fully ripe.

As bananas ripen, the starches they contain gradually convert into simple sugars. This is why ripe bananas taste sweeter than green or less mature bananas. While natural sugars are not necessarily harmful, consuming large amounts in a short period may cause blood sugar levels to rise more quickly.

According to the doctor, adding a fully ripe banana to a smoothie can significantly increase the drink’s simple carbohydrate load. When combined with other fruits, juices or sweetened ingredients, this may lead to a higher glycemic impact.

For individuals who are trying to manage blood sugar levels, maintain stable energy throughout the day or reduce overall sugar intake, this is an important consideration.

However, experts also note that the overall effect depends on the entire smoothie recipe. Smoothies that contain protein, healthy fats and fiber may slow the absorption of sugar and reduce sudden spikes in blood glucose.

Dr Sethi’s point is not that bananas are unhealthy but that people should be aware of how ripe bananas contribute to the overall nutritional profile of a smoothie.

His third concern involves calories.

Bananas contain more calories than many fruits commonly used in smoothies. A medium-sized banana generally contains around 100 calories, depending on its size. While this is not excessive, those calories can add up quickly when combined with other calorie-dense ingredients such as nut butters, yogurt, seeds or protein powders.

For individuals who are carefully monitoring calorie intake, a banana can substantially increase the total calorie count of a smoothie without them realizing it.

Many people view smoothies as light snacks, but some can contain as many calories as a full meal. Dr Sethi believes that understanding the calorie contribution of each ingredient helps people make choices that align with their health goals.

That said, calorie needs vary from person to person. Athletes, active individuals and people trying to gain weight may actually benefit from the extra calories and carbohydrates bananas provide. In such cases, bananas can be a valuable addition to a balanced smoothie.

It is also important to remember that bananas offer several nutritional benefits of their own. They provide potassium, vitamin B6, vitamin C and dietary fiber. Potassium supports heart health and muscle function, while fiber helps promote digestive health and feelings of fullness.

Because of these benefits, many nutritionists continue to recommend bananas as part of a healthy diet. The key message from Dr Sethi’s comments is not that bananas should be avoided entirely, but that they may not always be the best choice depending on the purpose of the smoothie.

For someone focused on maximizing antioxidants from berries, reducing sugar intake or lowering calories, alternative ingredients may be worth considering. On the other hand, for people seeking energy, convenience and a naturally sweet flavor, bananas can still be a nutritious option.

Ultimately, the healthiest smoothie is one that fits an individual’s nutritional needs and goals. Understanding how different ingredients affect the final drink can help people make more informed choices. While bananas remain a popular smoothie staple, Dr Sethi’s perspective serves as a reminder that even healthy foods may have advantages and drawbacks depending on how they are used.