A scientist said bananas ‘kill’ the benefit of blueberries. Is that true?
Can blending these popular fruits in a smoothie adversely affect the berries’ nutritional benefits? Experts weigh in

TL;DR
- A scientist claimed bananas, containing polyphenol oxidase, can reduce the beneficial polyphenols in blueberries.
- A study indicated lower blood levels of flavanols in participants who drank banana smoothies with added flavanols compared to mixed-berry smoothies.
- Experts note the study did not use bananas and blueberries together, had a small sample size, and measured flavanols, not the most abundant polyphenols in blueberries (anthocyanins).
- Nutrient interactions where one nutrient reduces the absorption of another are common but generally not a major concern for overall diet.
- Focusing on a varied diet rich in fruits and vegetables is more important than optimizing polyphenol absorption from every smoothie.
- If concerned, alternatives to bananas for smoothie creaminess include oats, yogurt, silken tofu, kefir, avocado, and frozen cauliflower.