A new study from the University of California, Davis, has revealed some surprising findings about how bananas can affect the health benefits of smoothies. The researchers found that the enzyme polyphenol oxidase (PPO) in bananas can significantly reduce the absorption of flavanols, a group of bioactive compounds that are good for your heart and cognitive health.
What are flavanols and why are they important?
Flavanols are a type of phytochemicals, which are natural substances found in plants that have various health effects. Flavanols are especially abundant in fruits such as apples, pears, berries, grapes, and cocoa. Flavanols have been shown to improve blood flow, lower blood pressure, reduce inflammation, and enhance brain function.
Smoothies are a popular way to consume fruits and vegetables, as they offer a convenient and delicious way to get essential nutrients. However, not all smoothies are created equal. The ingredients and preparation methods can influence how much flavanols and other phytochemicals are available for the body to absorb.
How does PPO affect flavanol absorption?
PPO is an enzyme that causes browning in fruits and vegetables when they are cut, bruised, or exposed to air. PPO can also react with flavanols and other phytochemicals, making them less bioavailable. This means that less of these beneficial compounds can reach the bloodstream and exert their effects.
The researchers from UC Davis wanted to test how different levels of PPO in smoothie ingredients affect flavanol absorption. They recruited 16 healthy volunteers and gave them three different treatments: a flavanol capsule as a control, a smoothie made with mixed berries (low PPO), and a smoothie made with banana (high PPO). The smoothies also contained water, ice, and sugar.
The researchers measured the levels of flavanols in the blood and urine of the participants after they consumed the treatments. They found that the banana smoothie resulted in an 84% reduction in flavanol levels compared to the control capsule. The berry smoothie had no significant effect on flavanol absorption.
What does this mean for smoothie lovers?
The findings of this study suggest that adding bananas to smoothies may not be the best idea if you want to optimize the health benefits of flavanols. Bananas have many other nutrients and benefits, but their high PPO activity may interfere with the availability of flavanols from other fruits.
The researchers recommend choosing ingredients with low PPO activity, such as pineapple, oranges, mangoes, or yogurt, when making smoothies with flavanol-rich fruits like berries. This way, you can enjoy the creamy texture and natural sweetness of your smoothie without compromising the flavanol content.
Alternatively, you can consume bananas separately from your smoothie or eat them whole instead of blending them. This may reduce the exposure of PPO to flavanols and other phytochemicals.
Smoothies are a great way to boost your intake of fruits and vegetables, but be mindful of what you put in them. By choosing ingredients wisely, you can maximize the health benefits of your smoothie and enjoy its delicious taste.