Bananas Could Be Wrecking Stop Sabotaging Your Smoothie: Why That Banana Might Be Blocking Nutrients

Think your morning smoothie is a health hero? According to new research, if you’re tossing in a banana, you could be unknowingly cutting one of its biggest benefits by more than 80%.

A recent study published in Food & Function and highlighted by SciTechDaily found that bananas, while nutritious on their own, can drastically reduce the absorption of flavan-3-ols (a powerful group of flavanols) when blended into smoothies. These compounds—found in foods like berries, cocoa, and tea—are linked to better aging, stronger mental health, and lower risk of frailty, especially in women, as confirmed by a 2025 American Journal of Clinical Nutrition study.

The problem? An enzyme called polyphenol oxidase (PPO) causes fruit like apples and bananas to brown, breaking down flavanols before your body can absorb them. In the study, participants who drank banana-based smoothies absorbed 84% fewer flavanols than those who consumed berry smoothies or flavanol capsules.

Even alternating sips of banana smoothie and flavanol-rich drinks didn’t fix the issue—PPO still got in the way.

So, what’s a smoothie lover to do? Keep the berries, skip the banana. If you’re craving more flavor or creaminess, try low-PPO alternatives like pineapple, mango, orange, or even a scoop of yogurt.

As lead researcher Gunter Kuhnle said, “The effect of a single banana was enough to destroy most of the flavanols in the berries.”

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