Recent findings suggest that adding bananas to your morning smoothie may reduce the health benefits of other fruits. Bananas contain high levels of polyphenol oxidase, an enzyme that breaks down flavanols, which are natural compounds associated with improved blood flow, brain function, and heart health. When bananas are blended with flavanol-rich fruits like berries, grapes, apples, or cacao, the body's ability to absorb these beneficial nutrients is diminished. Experts recommend reconsidering the combination of bananas with certain fruits to maximize nutritional intake.