Are Bananas “Bad” to Add to Smoothies?
— By Alex Gayton, Assistant EFNEP Coordinator & Social Media Coordinator, Expanded Food Nutrition and Education Program (EFNEP), University of Maine Cooperative Extension
Visit the University of Maine Cooperative Extension’s recipe website for the Blueberry Banana Smoothie recipe.
Blueberry Banana Smoothie has been my favorite smoothie combination for years. It’s simple, only needing five ingredients, packed with flavor, and a hidden ingredient that you might not expect. As much as I love this combo, a study has popped up online raising questions about whether we should add bananas to smoothies. Before we dive into that study, let’s cover some smoothie basics.
Basic Smoothie Combination
Liquid (water, milk, juice) + fruit + optional additions (leafy greens, nut butter, seeds, protein powder, or spices)
If you haven’t guessed yet, this Blueberry Banana Smoothie’s unexpected ingredient is fresh raw spinach. In addition to spinach, it contains milk, blueberries, a banana, and optional cinnamon. You might not believe me, but fresh raw spinach can be added to most smoothies and go unnoticed flavor-wise. Visibly, there will be a color change because of the vibrant green. So if you have kids who are usually suspicious of new food, like I do, you could make up a fun name for the smoothie, playing off the color or ingredients.
Benefits of Smoothies
- Smoothies are easy and convenient to make for breakfast or a snack.
- Smoothies are a fun way to add more fruits and vegetables to your diet and provide important vitamins and minerals.
- Kids can get involved in the kitchen by helping make smoothies, and it might encourage them to try new foods.
- There are endless flavor combination options. Here are some UMaine Extension smoothie recipes to try!
Are Bananas “Bad” to Add to Smoothies?
In April 2023, researchers at the University of California, Davis published a study titled Impact of polyphenol oxidase on the bioavailability of flavan-3-ols in fruit smoothies, ( Royal Society of Chemistry’s journal Food & Function). In this study, they used smoothies to test how various levels of polyphenol oxidase (PPO), an enzyme in many fruits and vegetables, affect the levels of flavanols (which is a type of antioxidant) in food to be absorbed by the body and used for your heart and brain.
To summarize the main takeaways from this study, if you’re blending fruits in a smoothie high in PPO (like bananas) with fruits high in flavanols (like berries, apples, or cocoa powder), the foods high in PPO are reducing the body’s ability to absorb the beneficial flavanols.
This is great information to know, but it’s important to understand:
- The study is not saying bananas are bad for you or bad to add to smoothies.
- What it is saying is that if you want the maximum benefit of flavanols from ingredients used in a smoothie, then you should combine them with other fruit options that have lower PPO, like berries, mango, oranges, and pineapple.
Bananas are still a great source of potassium and fiber, and provide a natural sugar that helps sweeten smoothies. If you’re drinking smoothies because you want maximal flavanol absorption, then consider alternatives to a banana in your smoothie, but if you are making smoothies for other reasons, like increasing fruit and vegetable intake or because you enjoy the flavor, continue using bananas. I know I will still be using bananas in my smoothies.