Banana Smoothie New findings have emerged indicating that the enzyme polyphenol oxidase (PPO) present in certain fruits, like bananas, can impede the absorption of heart-healthy flavanols. This effect is particularly prominent when these fruits are combined with flavanol-rich ingredients such as berries. To enhance the absorption of flavanols, a study recommends the use of ingredients with minimal PPO activity, such as pineapples or oranges, in smoothie preparation.
Fresh Insights to Optimize the Benefits of Fruit Smoothies for Your Well-being. Smoothies provide a convenient and delightful approach to integrating vital fruits and vegetables into one’s dietary regimen. But does the combination of banana and blueberries truly constitute an optimal choice? Emerging research from the University of California, Davis suggests that the amalgamation of specific ingredients in smoothies can significantly impact the extent to which your body derives nutritional advantages.
Published recently in the Food and Function journal by the Royal Society of Chemistry, this study employed smoothies as a vehicle to investigate how differing levels of polyphenol oxidase—an enzyme present in numerous fruits and vegetables—can influence the absorption of flavanols within the body. Flavanols, a category of bioactive compounds known for their cardiovascular and cognitive benefits, are naturally occurring in common smoothie components such as apples, pears, blueberries, blackberries, grapes, and cocoa.
Lead author Javier Ottaviani, who heads the Core Laboratory of Mars Edge, an entity under Mars, Inc., and concurrently serves as an adjunct researcher at the UC Davis Department of Nutrition, explained, “Our objective was to gain a pragmatic understanding of how a prevalent food item and its preparation, as seen in a banana-based smoothie, could impact the bioavailability of flavanols post-consumption.”
When you slice an apple or peel a banana, the flesh swiftly undergoes browning—an outcome of the activity of polyphenol oxidase, or PPO, an inherent enzyme in these foods. Browning becomes evident upon exposure to air, slicing, or mild bruising. The research team aimed to discern whether the consumption of freshly blended smoothies containing distinct PPO-rich fruits could influence the body’s access to flavanols.
Bananas vs. Berries Study participants were administered two types of smoothies for assessment: one derived from bananas, recognized for their elevated PPO levels, and the other from mixed berries, acknowledged for their minimal PPO content. Additionally, participants ingested a flavanol capsule as a control measure. Subsequent analysis of blood and urine samples gauged the presence of flavanols within the body following the consumption of both smoothie variations and the control capsule. The outcome revealed that individuals who consumed the banana-based smoothie exhibited an 84% reduction in flavanol levels compared to the control group.
“We were genuinely taken aback by the swift impact of introducing just one banana on the reduction of both flavanol levels within the smoothie and the ensuing absorption of flavanols in the body,” Ottaviani remarked. “This underscores how the interplay of culinary preparation and ingredient pairings can distinctly influence the assimilation of essential dietary components.”
In the preceding year, the Academy of Nutrition and Dietetics put forth a dietary guideline, urging individuals to incorporate 400 to 600 milligrams of flavanols into their daily intake for the betterment of cardiometabolic health. Ottaviani suggested that those striving to meet these flavanol targets should contemplate crafting smoothies that unite flavanol-rich fruits, like berries, with other elements exhibiting minimal PPO activity—examples being pineapple, oranges, mango, and yogurt.
Emphasizing that bananas still hold their position as a commendable fruit for direct consumption or inclusion in smoothies, Ottaviani elucidated that for enthusiasts of banana-infused smoothies or other produce with heightened PPO activity, such as beet greens, a prudent approach involves avoiding their combination with flavanol-rich counterparts like berries, grapes, and cocoa.
The revelations stemming from this study might act as a catalyst for prospective investigations into the impact of food preparation on flavanol content. For instance, Ottaviani pointed out that tea stands as a significant dietary source of flavanols, and varying preparation methods could yield differing levels of absorbable flavanols.
“This undeniably represents a domain warranting further exploration within the broader realm of polyphenols and bioactive compounds,” Ottaviani emphasized.
Citation: “Impact of polyphenol oxidase on the bioavailability of flavan-3-ols in fruit smoothies: a controlled, single-blinded, cross-over study” authored by Javier I. Ottaviani, Jodi L. Ensunsa, Reedmond Y. Fong, Jennifer Kimball, Valentina Medici, Gunter G. C. Kuhnle, Alan Crozier, Hagen Schroetera, and Catherine Kwik-Uribe, dated August 24, 2023, Food & Function. DOI: 10.1039/D3FO01599H
Contributions to the research were made by Jodi Ensunsa, Reedmond Fong, Jennifer Kimball, and Alan Crozier, all associated with the UC Davis Department of Nutrition, as well as researchers affiliated with the UC Davis Department of Internal Medicine, University of Reading, King Saud University, and Mars, Inc.
The study received financial support from a research grant provided by Mars, Inc., an organization collaborating with researchers to explore the potential health benefits of cocoa flavanols for humans.
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