Bananas and Flavanols: A Practical Health Question
Smoothies are a popular way to boost daily fruit intake, but a recent study raises an important question for smoothie lovers: could a common ingredient like bananas be dampening the health benefits of flavanols found in many fruit and cocoa products? The research, published in the Royal Society of Chemistry’s journal Food and Function, explored how polyphenol oxidase (PPO) — an enzyme present in many fruits and vegetables — affects the body’s ability to absorb flavanols. Flavanols are a subset of polyphenols linked to improvements in heart and brain health and are abundant in familiar smoothie ingredients such as apples, pears, berries, grapes, and cocoa.
The Core Finding: PPO Activity Can Reduce Flavanol Absorption
Led by Javier Ottaviani, director of the Core Laboratory of Mars Edge at Mars, Inc. and an adjunct researcher at UC Davis, the team asked a practical question: when a banana-based smoothie is blended, does the activity of PPO hinder the absorption of flavanols? The team compared two smoothie scenarios — one featuring banana, a fruit with relatively high PPO activity, and another built around mixed berries, which have lower PPO activity. A flavanol capsule served as a control to quantify how much of these compounds are absorbed in a standard supplement form.
How the Study Was Conducted
Participants consumed two smoothies in separate sessions: a banana-forward blend and a berry-forward blend. After consumption, researchers measured flavanol levels in blood and urine to gauge absorption. The results were striking: those who drank the banana smoothie exhibited an 84% reduction in flavanol levels compared with the group that took the flavanol capsule as a control. In other words, a single banana in the smoothie significantly curtailed the body’s uptake of these beneficial compounds.
What This Means for Daily Eating
Ottaviani emphasized that the finding demonstrates how common food preparation and combinations can influence nutrient availability. While bananas are nutritious and offer many health benefits, their high PPO activity can interact with flavanol-rich ingredients and limit absorption. The practical takeaway is not to abandon bananas, but to be mindful of pairings if the goal is to maximize flavanol intake from food sources.
Understanding Flavanols and Their Benefits
Flavanols are natural plant compounds found in cocoa, berries, apples, and grapes. They belong to the broader family of polyphenols and are associated with several potential health benefits when consumed regularly. Research suggests flavanols may support healthy blood flow, contribute to cognitive function, and help mitigate inflammation. The evidence points to a beneficial role for flavanols in heart and brain health, but the degree of benefit depends on how well these compounds are absorbed and utilized by the body.
Smart Pairings: How to Maximize Flavanol Intake
Dietitians and researchers highlight practical strategies for boosting flavanol intake. The 2022 recommendations from the Academy of Nutrition and Dietetics suggest a daily target of 400 to 600 milligrams of flavanols for cardiometabolic health. Ottaviani suggests pairing flavanol-rich fruits with foods that have low PPO activity to minimize the enzyme’s impact. For example, combining berries with pineapple, oranges, mango, or yogurt can help retain more flavanols than mixing them with high-PPO fruits like bananas or beet greens.
The take-home message is nuanced: enjoy banana smoothies for their nutrition, but if your goal is to maximize flavanol absorption, consider blending berries with low-PPO ingredients or enjoying flavanol-rich foods separately. The broader implication is that even common meal choices deserve thoughtful composition to optimize nutrient uptake.
Looking Ahead: A Field Worth Deeper Investigation
Ottaviani believes this line of inquiry could unlock new understanding of how food preparation affects nutrient absorption across various bioactive compounds. For instance, tea is another major flavanol source, and brewing methods could similarly influence how much of these compounds the body can absorb. The study highlights an area ripe for more research within polyphenols and bioactive compounds, with potential implications for dietary guidelines and personal nutrition strategies.
Researchers involved in the study include Jodi Ensunsa, Reedmond Fong, Jennifer Kimball, and Alan Crozier, with affiliations spanning UC Davis, the University of Reading, King Saud University, and Mars, Inc. The project was funded by Mars, Inc., reflecting ongoing industry interest in understanding how cocoa flavanols interact with everyday foods. As the authors note, more work is needed to generalize these findings and translate them into practical dietary advice for various populations.
