A 2023 study published in Food & Function by Ottaviani et al. revealed that polyphenol oxidase (PPO)—an enzyme abundant in bananas—can reduce antioxidant absorption from blueberries by up to 84%. Here’s why this matters: PPO oxidizes polyphenols, the plant compounds in berries responsible for fighting inflammation, aging, and disease. When blended together, bananas neutralize key antioxidants before they reach your bloodstream. What to do instead: • Eat bananas and berries at least 30 minutes ap