INDIANAPOLIS, Ind. (WOWO) — A common smoothie ingredient is at the center of a new nutrition debate after researchers found bananas may reduce the amount of beneficial plant compounds the body absorbs from some berries.
The discussion began after a viral social media conversation highlighted research examining whether bananas could interfere with polyphenols — natural compounds found in foods like blueberries that have been linked to benefits involving heart, brain and gut health.
Fox News Digital reported that Dr. Rhonda Patrick, a biomedical scientist and founder of FoundMyFitness, discussed the issue during a July appearance on the “Mel Robbins Podcast.” Patrick explained that bananas contain an enzyme called polyphenol oxidase, or PPO, which can break down polyphenols. The same enzyme is responsible for the browning that happens when certain fruits are cut open and exposed to air.
Patrick said she avoids adding bananas to her smoothies because she wants to preserve as many of the beneficial compounds found in berries as possible. Instead, she said she uses ingredients such as avocado to create a creamy texture while adding other nutrients.
The research behind the discussion comes from a 2023 study published in the journal Food & Function. Researchers examined how the body absorbed plant compounds after participants consumed different combinations of foods.
The study involved eight healthy men who, on separate occasions, consumed either a banana smoothie, a berry smoothie with lower levels of PPO, or a flavan-3-ol supplement mixed with milk.
Researchers found that the banana smoothie resulted in significantly lower levels of absorbed flavan-3-ols compared with the supplement, with blood tests showing about an 84% reduction in peak concentrations of those compounds.
However, experts caution that the findings do not mean people should stop adding bananas to smoothies.
Los Angeles-based registered dietitian nutritionist Ilana Muhlstein told Fox News Digital the results are “interesting,” but she said they should be interpreted carefully because of the study’s small size and design.
“It doesn’t mean the smoothie loses all of its health benefits,” Muhlstein said. “You’re still getting fiber from the banana, and many other beneficial nutrients from polyphenol-rich fruits.”
Muhlstein noted the study did not specifically test a banana-and-blueberry smoothie. Researchers used a standardized cocoa-derived flavanol supplement rather than whole berries, which may interact differently in the body.
Patrick later addressed the online reaction, saying people can still include bananas in smoothies but should understand that the fruit may reduce some of the polyphenols available from certain berries.
“Bananas are nutritious, I eat them, and this is not a reason to stop,” Patrick said in a follow-up social media post. She added that people focused on maximizing berry polyphenols may want to consider the combination of ingredients they use.
Nutrition experts say the findings are more complicated than simply labeling bananas as unhealthy.
New York-based certified holistic nutritionist Robin DeCicco told Fox News Digital that nutrition recommendations depend on a person’s overall diet and health goals. She said many Americans would benefit more from adding nutrient-rich foods like fruits and vegetables rather than worrying about small differences in smoothie ingredients.
“It doesn’t need to be so complicated all the time,” DeCicco said. “If you’re eating a banana instead of french fries, that’s good.”
Experts say people trying to increase their intake of polyphenols may consider alternatives such as avocado, frozen zucchini or Greek yogurt to provide a creamy smoothie texture while maintaining higher levels of certain plant compounds.
Researchers say additional studies are needed before drawing broad conclusions about how common smoothie combinations affect long-term health benefits.
