Researchers got participants to drink a banana-based smoothie with naturally high PPO activity, and a smoothie made with mixed berries – which have naturally low PPO activity. They also took a flavanol capsule as a control.

After analysing participants’ blood and urine samples, scientists were able to measure how much flavanols were present in the body after consuming the smoothie samples and capsules. The result? Those who drank the banana smoothie had 84% lower levels of flavanols in their body.

“We were really surprised to see how quickly adding a single banana decreased the level of flavanols in the smoothie and the levels of flavanol absorbed in the body,” said lead author Javier Ottaviani. “This highlights how food preparation and combinations can affect the absorption of dietary compounds in foods.”

Bananas may be making your morning smoothie less nutritious – here’s why