The Impact of Polyphenol Oxidase on Flavanol Absorption

Polyphenol oxidase (PPO) is a natural enzyme found in many fruits and vegetables. But how does this enzyme affect the body’s absorption of bioactive compounds like flavanols? This question was the focus of a study recently published in the Journal of the Royal Society of Chemistry, which explored the effect of PPO on the body’s ability to absorb flavanols, compounds linked to heart and brain health.

The Interaction Between Fruits and PPO

When fruits like apples or bananas are cut, they quickly turn brown due to the reaction of PPO with oxygen. This reaction is more than just a visual observation; it affects how well the body absorbs flavanols in these fruits. Flavanols are important natural compounds that contribute to improved blood flow, memory support, and reduced inflammation.

Researchers from the University of California, Davis, questioned whether the activity of this enzyme affects flavanol absorption when fruits are blended into smoothies. They conducted an experiment to compare the effect of blending bananas, which have high PPO activity, with berries, which have low PPO activity.

Smoothie Experiment Results

Participants in the study consumed two different types of smoothies: one containing bananas and the other a mix of berries, along with a flavanol capsule for comparison. Subsequently, flavanol levels in blood and urine were measured. The results were striking, showing that consuming the banana smoothie led to an 84% reduction in flavanol levels compared to the reference capsule.

These findings highlight the role that food preparation methods play in the absorption of nutritional compounds. The study’s lead researcher, Javier Ottaviani, explained that adding just one banana to a smoothie can significantly reduce the amount of flavanols absorbed by the body.

Choosing the Right Fruits

To maintain adequate flavanol levels, it is recommended to blend flavanol-rich fruits like berries with ingredients that have low PPO activity, such as pineapple, orange, mango, or yogurt. In 2022, the Academy of Nutrition and Dietetics recommended consuming 400 to 600 mg of flavanols daily for cardiovascular health.

Although bananas remain nutritious, it is preferable not to mix them with flavanol-rich fruits such as berries, grapes, or cocoa. The same principle applies to other foods with high PPO activity, like beet greens.

Conclusion

This study opens the door for further research on how food preparation affects nutrient absorption. For instance, tea is a major source of flavanols, and its preparation method may influence the availability of these compounds for absorption. This area deserves more attention in the study of polyphenols and bioactive compounds in general. The study emphasizes the importance of carefully selecting fruit combinations to achieve the desired health benefits from flavanols.