Smoothies are often seen as a convenient way to consume fruits and vegetables, however, a 2024 study showed that adding just one banana can significantly reduce the drink's benefits.
The main reason is the reduction of flavanol content, beneficial compounds found in apples, berries, grapes, and cocoa. These substances positively affect the functioning of the heart and brain.
Bananas contain the enzyme polyphenol oxidase (PPO), which causes fruits to darken in the air and worsens the absorption of flavanols by the body. According to an experiment, participants who consumed a banana smoothie had flavanol levels in their blood that were 84% lower than those who took them in capsule form. Meanwhile, berry-based smoothies retained almost all of their benefits.
This does not mean that bananas are harmful: they are rich in potassium, fiber, and vitamins. However, if you want to get the most benefit from your smoothie, it's better not to combine bananas with foods rich in flavanols. Instead, you can use ingredients with low PPO content—pineapple, oranges, mango, or yogurt.
