UC Davis Study Finds Bananas Cut Smoothie Flavanol Absorption by 84%

2 articles · Updated · ScienceDaily · May 24

An 84% drop in flavanol levels was seen when participants drank a banana-based smoothie versus a flavanol capsule control, while a mixed-berry smoothie produced levels similar to the control.
UC Davis researchers tied the effect to bananas' high polyphenol oxidase activity—the enzyme behind fruit browning—which appears to degrade flavanols from berries, grapes, cocoa and other ingredients.
A second test with 11 participants still showed reduced flavanol absorption even when banana and flavanols were kept separate before intake, suggesting the interaction may continue after consumption, possibly in the stomach.
The controlled study was small—eight healthy men in the first part—and researchers said bananas remain nutritious, but are a poor smoothie choice when the goal is maximizing the 400-600 milligrams of daily flavanols recommended for cardiometabolic health.
For flavanol-focused smoothies, the team suggested pairing berries with low-PPO ingredients such as pineapple, oranges, mango or yogurt, highlighting how food combinations can alter nutrient uptake.

A candy company funded this banana study. Is this crucial health advice or just clever marketing for its own flavanol products?

Why does adding a banana to your smoothie erase 84% of the health benefits from the berries inside?