The Surprising Truth Behind a Popular Combination
For years, a banana and berry smoothie has been a staple of healthy eating, offering a creamy texture and antioxidant boost. However, recent research indicates that blending these fruits may not be optimal for absorbing certain antioxidants.
The Science of Polyphenol Oxidase (PPO)
A key factor in this interaction is polyphenol oxidase (PPO), an enzyme also responsible for fruit browning. A study by the University of California, Davis, and the University of Reading showed that banana PPO reduces the bioavailability of flavan-3-ols from berries when blended. These flavanols, found abundantly in berries like blueberries and strawberries, are linked to cardiovascular and cognitive health. Bananas have high PPO activity which, when blended with berries, causes the degradation of flavanols. The study found an 84% lower absorption of flavanols in subjects consuming a banana and berry smoothie compared to a flavanol capsule. Even unblended but simultaneous consumption showed this effect, suggesting PPO remains active in the stomach.
Is it a Health Risk? Context is Key
Combining bananas and berries is not unsafe. The concern is about lost opportunity for flavanol intake. If maximizing berry flavanols is your goal, a banana-berry smoothie may not be the most effective method. However, both fruits still provide other nutrients like potassium, vitamin B6, and fiber from bananas, and vitamin C and other antioxidants from berries. For individuals with a varied diet, the impact is likely minor.
Maximizing Flavanol Intake in Smoothies
To enhance berry flavanol absorption in smoothies, opt for low-PPO fruits or ingredients.
Low-PPO fruits and ingredients for smoothies:
- Pineapple: A sweet, tangy option.
- Oranges: Citrus fruits are low in PPO and high in vitamin C.
- Mango: Offers creaminess with low PPO.
- Yogurt or Greek Yogurt: Provides a low-PPO base.
- Spinach or Kale: Leafy greens have negligible PPO.
- Citric Acid: Lemon or lime juice can inhibit PPO.
Digestive Considerations and Common Myths
Traditional theories about combining fruits with different digestion times and potential digestive upset lack strong scientific evidence. However, individuals with conditions like IBS may experience discomfort due to fiber or sugar content. For most healthy individuals, fruit combinations do not cause significant digestive issues.
Banana vs. Berry Smoothie: Nutrient Absorption Comparison
| Feature | Classic Banana & Berry Smoothie | Low-PPO Alternative & Berry Smoothie |
|---|---|---|
| Taste & Texture | Creamy, sweet, and classic. Banana provides natural thickness. | Flavor profile is more varied, often brighter. Ingredients like mango or yogurt provide creaminess. |
| Flavanol Absorption | Significantly reduced due to high PPO enzyme activity in bananas. | High absorption maintained by using low-PPO fruits like mango, pineapple, or oranges. |
| PPO Activity | High due to the banana content, which initiates the reaction that degrades flavanols. | Low, ensuring that flavanols are not broken down before they can be absorbed by the body. |
| Nutrients Preserved | High amounts of potassium, vitamin B6, fiber (from banana), and other vitamins and minerals are retained. | High amounts of antioxidants, vitamin C, fiber (from berries), and other vitamins and minerals are retained. |
| Best For... | Individuals prioritizing taste and fiber or not concerned with flavanol absorption from that specific meal. | Those aiming to maximize the cardiovascular and cognitive benefits specifically from berry flavanols. |
Practical Advice for Everyday Eating
For most people, the choice depends on personal preference and nutritional goals. Enjoying a banana and berry smoothie is still a healthy option compared to many processed foods.
To maximize berry flavanol intake, consider these alternatives:
- Separate Consumption: Eat fruits at different times.
- Low-PPO Smoothie Swap: Use low-PPO fruits with berries.
- Consider Whole Fruit: Blending has a greater impact than eating whole fruits together.
Understanding food pairing helps align meals with health objectives. This study offers valuable insight into nutrient bioavailability.
Conclusion
While not harmful, combining bananas and berries, particularly in smoothies, reduces the absorption of beneficial berry flavanols due to banana's high PPO enzyme. The combination still offers other nutrients. For maximizing flavanol intake, low-PPO alternatives like mango or pineapple with berries are more effective. The best choice depends on individual priorities, and a varied diet is crucial for overall nutrition.
