Researchers have found that adding bananas to berry smoothies may greatly reduce the body's ability to absorb flavanols, healthy plant compounds linked to better heart and brain health.
In a study published in the journal Food & Function, researchers tested smoothies made with ingredients containing different levels of an enzyme called polyphenol oxidase (PPO). Notably, bananas contain high levels of PPO, while mixed berries contain low levels.
"We sought to understand, on a very practical level, how a common food and food preparation like a banana-based smoothie could affect the availability of flavanols to be absorbed after intake," said lead author Javier Ottaviani.
Participants drank three different drinks - a banana smoothie, a mixed berry smoothie, and a flavanol capsule used for comparison. Researchers then checked blood and urine samples to measure how much flavanol the body absorbed.
The results showed that people who drank the banana smoothie had 84% lower flavanol levels compared to the capsule control. Meanwhile, people who drank the mixed berry smoothie had flavanol levels similar to the capsule group.
"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," Ottaviani noted. "This highlights how food preparation and combinations can affect the absorption of dietary compounds in foods."
In another test, participants consumed flavanols along with a high-PPO banana drink, but the ingredients were kept separate until consumption. Even then, flavanol absorption was reduced, suggesting that the enzyme may continue affecting flavanols after entering the stomach.
The study emphasized that the way foods are combined can affect how much nutrition the body actually absorbs.
For comments and feedback: editorial@rttnews.com