The Science Behind the 'Canceling Out' Claim
Recent research has brought a common smoothie combination under scrutiny. The core of the issue lies with a natural enzyme found in bananas, called polyphenol oxidase (PPO). PPO is the enzyme responsible for browning in many fruits, including bananas, when they are exposed to oxygen.
The Role of PPO and Flavanols
Blueberries are well-known for their antioxidant properties, primarily from compounds called flavanols. The PPO in bananas can break down these flavanols when they are mixed together, particularly in a blended form where the enzyme is released and thoroughly combined with the berries. The study found that this breakdown significantly decreased the flavanol levels available for the body to absorb. It is important to note that this effect was specifically measured in the context of blended smoothies, not when eating the whole fruits separately.
Context Is Key: The Study's Limitations
While the 2023 study offers valuable insight, it is essential to consider the context and limitations of the research. First, the study was small in scale, with only a limited number of participants. Second, the dramatic reduction in flavanol absorption was only observed when the fruits were blended. The researchers did not assess whether eating whole bananas and whole blueberries at the same time produces the same effect. For most people, a well-rounded diet is far more important than worrying about one specific food combination. Both bananas and blueberries offer a host of health benefits independently and are valuable additions to any diet.
Nutritional Comparison: Banana vs. Blueberry
To put the “canceling out” claim in perspective, it helps to examine the nutritional profile of each fruit. Both offer distinct and complementary benefits.
| Nutrient | Banana (approx. 100g) | Blueberry (approx. 100g) |
|---|---|---|
| Calories | 89 kcal | 57 kcal |
| Carbohydrates | 22.8 g | 14.5 g |
| Dietary Fiber | 2.6 g | 2.4 g |
| Potassium | 358 mg (10% DV) | 77 mg |
| Vitamin B6 | 0.4 mg (31% DV) | 0.05 mg |
| Vitamin C | 8.7 mg (10% DV) | 9.7 mg (11% DV) |
| Antioxidants | Antioxidants present | Anthocyanins (high) |
Optimizing Your Fruit Combos
If your primary goal is to maximize the antioxidant intake from your blueberries, particularly when making a smoothie, there are ways to adapt your recipes. The key is to pair them with fruits that have a lower PPO content. Suggested low-PPO pairings include:
- Pineapple
- Mango
- Oranges
- Cherries
Alternatively, you can add probiotics like yogurt or kefir to your blueberry smoothie to create a powerful intestinal combination. Blending blueberries with other antioxidant-rich berries, such as strawberries or raspberries, also avoids the PPO interference.
Whole Fruits vs. Blended
The research specifically targeted the effect of blending. When a fruit is blended, its cellular structure is broken down, releasing enzymes like PPO that would normally be contained within the cell walls. When you eat whole fruits, this breakdown and mixing occur more slowly and less thoroughly, potentially minimizing the antagonistic effect. Therefore, enjoying a banana and a handful of blueberries separately or together in a fruit salad is likely a different, and less impactful, scenario than blending them into a smooth puree.
Conclusion: Don't Fret Over Your Smoothie
Ultimately, whether bananas and blueberries cancel each other out depends on the preparation method and your specific nutritional goals. While blending them can reduce the absorption of some flavanols, it does not erase the overall health benefits of either fruit. Both bananas and blueberries remain incredibly nutritious and excellent for your health. For most people, the pleasure and nutritional value of a banana-blueberry smoothie far outweigh the marginal loss of some compounds. For those focused on maximizing specific antioxidant intake, consider enjoying the fruits separately or pairing blueberries with lower-PPO alternatives in your blended drinks. The biggest takeaway from the research is a greater appreciation for how food preparation can influence nutrient availability. For more detailed information on flavanols and health, see this article from Medical News Today: Benefits and health risks of bananas - Medical News Today.
