New Research Reveals Why You Shouldn’t Add a Banana to Your Smoothies

Banana Smoothie

Researchers have found that the enzyme polyphenol oxidase (PPO) in certain fruits like bananas can reduce the absorption of heart-healthy flavanols, especially when combined with flavanol-rich ingredients like berries. The study suggests choosing ingredients with low PPO activity, such as pineapple or oranges, when making smoothies to optimize flavanol absorption.

New research helps maximize the health benefits of fruit smoothies.

Smoothies offer a delicious and easy method to incorporate essential fruits and vegetables into your diet. But is a banana and blueberry smoothie the best combo? New research from the University of California, Davis, suggests that blending certain ingredients in smoothies can influence whether your body is getting a nutritional boost.

The study, recently published in the Royal Society of Chemistry’s journal Food and Function, used smoothies to test how various levels of polyphenol oxidase, an enzyme in many fruits and vegetables, affect the levels of flavanols in food to be absorbed by the body. Flavanols are a group of bioactive compounds that are good for your heart and cognitive health and are naturally found in apples, pears, blueberries, blackberries, grapes, and cocoa — common smoothie ingredients.

“We sought to understand, on a very practical level, how a common food and food preparation like a banana-based smoothie could affect the availability of flavanols to be absorbed after intake,” said lead author Javier Ottaviani, director of the Core Laboratory of Mars Edge, which is part of Mars, Inc., and an adjunct researcher with the UC Davis Department of Nutrition.

Slice an apple or peel a banana and the fruit will quickly turn brown. That happens because of polyphenol oxidase, or PPO, an enzyme naturally present in those foods. The browning occurs when the food containing that enzyme is exposed to air, cut, or bruised. The researchers wanted to know whether consuming freshly prepared smoothies made with different PPO-containing fruits impacted the amount of flavanols available to the body.

Bananas Versus Berries

The researchers had participants drink a smoothie made with banana, which has naturally high PPO activity, and a smoothie made with mixed berries, which have naturally low PPO activity. Participants also took a flavanol capsule as a control. Blood and urine samples were analyzed to measure how much flavanols were present in the body after ingesting the smoothie samples and capsule. The researchers found that those who drank the banana smoothie had 84% lower levels of flavanols in their bodies compared to the control.

“We were really surprised to see how quickly adding a single banana decreased the level of flavanols in the smoothie and the levels of flavanol absorbed in the body,” Ottaviani said. “This highlights how food preparation and combinations can affect the absorption of dietary compounds in foods.”

Last year, the Academy of Nutrition and Dietetics issued a dietary recommendation, advising people to consume 400 to 600 milligrams of flavanols daily for cardiometabolic health. Ottaviani said that people who are trying to consume those flavanols should consider preparing smoothies by combining flavanol-rich fruits like berries with other ingredients that also have a low PPO activity like pineapple, oranges, mango, or yogurt.

He also said bananas remain a great fruit to be eaten or consumed in smoothies. For those who want to consume smoothies with bananas, or other high PPO activity fruits and vegetables such as beet greens, the suggestion is to not combine them with flavanol-rich fruits such as berries, grapes, and cocoa.

The findings of this study could spur future research into how other foods are prepared and the effects on flavanols, for example, Ottaviani said tea is a major dietary source of flavanols and depending on how it is prepared, a different amount of flavanols would be available for absorption.

“This is certainly an area that deserves more attention in the field of polyphenols and bioactive compounds in general,” said Ottaviani.

Reference: “Impact of polyphenol oxidase on the bioavailability of flavan-3-ols in fruit smoothies: a controlled, single blinded, cross-over study” 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, 24 August 2023, Food & Function.
DOI: 10.1039/D3FO01599H

Jodi Ensunsa, Reedmond Fong, Jennifer Kimball, and Alan Crozier, all affiliated with the UC Davis Department of Nutrition and researchers affiliated with the UC Davis Department of Internal Medicine, University of Reading, King Saud University, and Mars, Inc. contributed to the research.

The study was funded by a research grant from Mars, Inc., which collaborates with researchers to study the potential benefits of cocoa flavanols for human health.

68 Comments on "New Research Reveals Why You Shouldn’t Add a Banana to Your Smoothies"

  1. Fascinating,thanks

  2. This is flawed. Blueberries have flavonol, so of course the mixed berries smoothie will be higher than one with just a banana. They should have done 3 cell study where the had a smoothie with banana and mixed berries in one smoothie as the study title suggests.

    • Seems like I’m not understanding when they actually measure the amount of flavonols. I thought it read that they measured the amount of slave knowledge and a urine sample and found that there weren’t many there perhaps they were all absorbed by the body and the banana makes them be absorbed better?

      • *flavonols in a urine sample

        Not sure how to edit the first reply I put in. I don’t know how it got slave knowledge from flavonals. Haha

        • HAHAHA I see how it did. Flave got autocorrected as slave and nol got auto corrected as knowledge. That’s so funny

          • Christopher Fay | August 26, 2023 at 8:09 pm |

            It’s all in the Etymology! The truth is starting us in the face!. The new variant is called:
            ID 10 T oR just IDIOT for short.

  3. You know,I really don’t care what any study says, I’m going to continue to have a wild blueberry smoothy with ripe bananas, so l will also agree with the previous post that the study is flawed…

  4. Cooking the banana first would denature this enzyme.

  5. Simply solution. I will eat my bananas later in the day as a snack instead of in my smoothie

    • Funny.. “New research reveals why you shouldn’t add a banana to your smoothie” then more on scitech daily “Climate change could significantly impact global banana yields” ..just saying..

      • How does mixing bananas and berries affect bioavailability of all nutrients in both fruits? Why cherry pick just flavonol and should maximum flavonol absorption be prioritized over all other beneficial nutrients obtained from adding a banana? How does that depend on the specific health benefits desired by each individual? Of course all of that is too complicated to study but it goes to show you can’t extrapolate meaningful life advice from this study as the article suggests.

  6. Everything is fear-based in media…. Just eat it.

  7. So flavinol is the only important nutrient in the fruit? Please spare me. There are thousands of combinations of micronutrients in everything you eat. I’m sure the banana has all kinds of other beneficial things that the berries don’t.

  8. Found this very interesting and I will be looking to include more flavanols into my diet at a different time of day that I drink my banana/strawberry/blueberry/coco smoothies.

  9. Its amazing we ever survived without dietary micro management. Don’t worry about it there will another study down the road soon extolling the benefits of bananas.

  10. My thought was “besides the fact that bananas are gross?” I find that flavour-wise they tend to overwhelm everything else in the smoothie too. It’s annoying how everytime I order one I always need to specify NO BANANAS, I think it’s done for texture and because bananas are inexpensive and sweet… but I’m mildly allergic to them as well, so maybe I’m more sensitive to the taste.

  11. Love how this “nutrition” study was funded by Mars, Inc. This is one of the problems with trusting most nutritional research, including studies conducted by the US government. The giant food companies are in the pockets of the universities, the FDA, etc., conducting the research. The bias is glaring.

    • Erica J. Mandell | August 26, 2023 at 7:43 pm | Reply

      I think you got it reversed: The “researchers” are financially controlled by the corporate interests. But I could see how some substances may affect how others work. I agree with the poster who said, just eat the banana later.

    • So it’s better to eat bananas later after the smoothie

  12. Seriously..just focus on eating healthy foods and forget all that other nonsense. Stressing over I can’t mix this w that is far worse than POSSIBLY missing out on some flavanols. I tend to think there’s more going on than they’ll ever understand anyway..with the hundreds/thousands of chemicals in each individual food, w endless possible combinations and reactions. How many times have they assumed something only to find out it wasn’t really how/what they assumed..

  13. I agree with few of the comments that are sensible.just get what’s informative to you and be grateful for your food and health.👍

    • Funny..”New research reveals why you shouldn’t add a banana to your smoothie” then more on scitechdaily “Climate change could significantly impact global banana yields” …just saying…

  14. I wonder if this applies to soft serve deserts made with the Yonana machine. Frozen banana and frozen fruits, no additional ingredients. It is so similar.

  15. The flavanol capsule that was taken is throwing the study off.

  16. IncredulousMinion | August 26, 2023 at 3:45 pm | Reply

    Study says apples have both flavanoids and PPO’s. So apparently you should and shouldn’t eat apples with your smoothie. Or maybe not at all. Gonna have to think about all this as I eat my Big Mac Happt Meal with pesticide coated apple slices instead of fries. After which I’ll have a banana berry smoothie and contemplate M&M Mars’contribution to nutrition before my bedtime beer.

  17. It’s like
    When you mix certain essential minerals with other minerals etc.
    The iron is bound to the other thing biochemically and is simply excreted without being absorbed.

    Humans where is your grey matter – maybe your Maacas cows lived in intensive grain fed pens, didn’t eat grass at all, and so had no Omega, 3 in their fat for you to ingest so your brains could work properly.
    It’s a thing – our brains are 10% fat, and a fair whack of it is a omega 3.
    Reduces brain inflammation too,esp if you eat blue and other berries – but as long as you don’t eat banana at the same time!!
    Have banana smoothies at a different time (bit like how you don’t sleep and eat at the same time).
    And maybe do Year 11 Chemistry and Biology courses rather than Tech this, Tech that. We’re animals not robots.

  18. What an idiotic study. Here is my strategy: Eat fewer foods sold by corporations with doctors on their payroll, and eat more banana smoothies!

  19. Funny how Mars INC conducted a study that Cocoa was best without adding banana. Go figure!

  20. Good Lord please stop this nonsense studies & I’ll agree with the comments I’m still having my smoothiesss my way bozo studies …watching when bananas attack ..hahaha

  21. And you wonder why everyone hates California and many are leaving! I’ll bet this crap was funded with a grant from tax dollars. Maybe you idiots should be spending money more wisely like trying to find Sasquatch or figuring out the disadvantages of bleaching your butthole.

    • Everyone doesn’t HATE California. Everyone EXCEPT MAGAts hate imbeciles.

    • Go back to bed u MAGA sheep grandpa

      • A lot of hate speech. But they didn’t say add Mars, Inc. products to your smoothie,just cocoa. It can, of course, be a conspiracy. Can, not is. But they specifically stated that bananas, not cease to eat, can negatively affect your berries smoothie. Just eat the banana later.
        What’s so hard?

  22. Can we mix banana and milk Ayurveda?

    “Banana should not be eaten with milk, curds, or buttermilk because the combination can diminish digestion and produce toxins in the body. Eating this combination can lead to cold, cough, and allergies,” says the Ayurveda expert. Curds can cause swelling and aggravate blood (rakta), pitta, and kapha

    • Research seems to think that there’s one reason only to drink smoothies; flavanols; probably not in the Top 10. Banana composition also changes between green and ripe. No causality demonstrated, either. Filed under anecdotal & irrelevant.

  23. I could not find the paper that was mentioned in this article. The method described is extremely suspect, unreliable and generally meaningless. I suspect you’ve been had.

    • what do you mean you couldn’t find the paper described in the article. The title of the article is literally given as well as a link at the end of the article.

  24. In another year or two they will release the results of another government funded study that recommends adding bananas to your smoothie!

  25. I’ll tell you what! Everybody I see is obese everywhere I go nowadays so a better study would be to see how much banana a person should eat each day and whether anybody eats any fruit at all!!!!

    • That is downright rude. Sounds like you are very self-righteous. Maybe consider possibly positive opinions on these topics.

      • I have a banana tree growing right outside my kitchen window, of course the bananas never get mature enough to use. I wonder if the PHDs in California can predict if global warming continues at the current pace, how many years from now my bananas will become mature enough to blend in my smoothie, which I call shakes and make em with ice cream or on occasion make em with lime and tequila and refer to them as margaritas. Hopefully by the time my shakes and margaritas become smoothies my weight will still be 140# and my mind won’t have jelled enough from the margaritas so that I might consider whether I should replace the banana tree with a blackberry bush in order to get the recommended amount of flavinols from my margarita smoothies and my shake smoothies.

  26. It may help to actually read the entire article and not focus on a particular part that you may not agree with.
    The article clearly states “bananas remain a great fruit to be eaten or consumed in smoothies. For those who want to consume smoothies with bananas, or other high PPO activity fruits and vegetables such as beet greens, the suggestion is to NOT combine them with flavanol-rich fruits such as berries, grapes, and cocoa.”
    And for the record I do reside in California near the University that conducted this study and many others that have proven quite beneficial to the general health of humans living in all parts of our world.

  27. In the title it says “shoulnt” thats a long way from “dont”. So its just a suggestion. We are all going to do what we want to any how. Some wil still do it, some wil not and some will do just cause it says you “SHOULDNT”. Its your body. Do as you see fit… The study is already done, why cry over spilled milk. Take care everyone.

  28. Inquiring Mind | August 27, 2023 at 1:01 pm | Reply

    What about eating the same fruits together and NOT in a smoothie?

  29. I’m certain (hiccup!) this Jose Cuervo Tequila (hiccup!) has jus the purfect blend of dem flavonoid thingys when stirred in wif some lime wedgies and some crushed ice(hiccup!) I won’t need no nanners or berries at tal in my smoovies! Dats wat I thank!

  30. Oh please. Eye roll.

  31. So far no one has told me which one came first, the chicken or the egg. Because of that I will eat my banana whenever I feel like it.

  32. I have do many questions, but my initial thoughts are… There is no practical reason to avoid this classic combination of fruits, ESPECIALLY since flavonols are extremely beneficial to gut health. There is actually a benefit to be realized here: less absorption of flavonols into the bloodstream means more availability of flavonols for gut microbiota. Of course, that will reduce the benefit to your other organ systems. This is why variety in diet is important: different combinations of foods, especially in smoothie combinations will allow us to experience a multitude of health benefits. Both strategies lead to tremendously positive health outcomes. There’s no need to favor X over Y in any general sense here.

  33. Quite frankly, I don’t care what the research says. I like the taste of banana in my smoothies. And honestly, i think the headline is a bit much. If it isn’t actual poison, don’t tell me what i should and shouldn’t eat. If i want to eat grass and tree bark thats my damn paragotive.

  34. I dont know about losing banana I made shames 1 times a day with banana, mixed berries, baby spinach , and kale for 5 weeks..I went to Dr’s had blood work and was shocked to see my cholesterol was down 75 POINTS. And vitamin D up 20 points…No I didn’t change diet any..but will continue recipe each morning.

  35. These people cannot be trusted because they also have an article regarding the fake climate change agenda and its impact on banana yields. FYI CO2 is at it’s lowest amount in the last 600 million years. That is a scientific fact.

  36. I tried leaving the banana out of my morning smoothie that contains both blueberries and cocoa with 2 cups of liquid plus protein powder and it got so thick it was hard to drink. When I put it back in the blender and added a banana, it became drinkable. I wonder what the chemical explanation would be for this.

  37. So, my current smoothie is greens k usually barley greens or wheat grass, spiruline, beet greens, magnesium, protein powder, psyllium, maca powder, chia seeds, collagen, and then fruits, usually banana and mixed berries. So if I’m not supposed to put bananas and mixed berries together am I supposed to put bananas with all this or am I supposed to put fruit with all of this? How do I know those other items if they are high in polyphenol oxidas?

  38. Didn’t they(not in this article) say bananas ARE berries? Why are they so different from other berries now that they prevent the benefits other berries provide?

  39. The number of people in the comments who think the fact that this study focused on flavinols somehow means that the scientific community considers ONLY flavinols to be important. 😂 Also the comments that think that Mars funding this study somehow changes how chemistry works, and the ones that cocoa and chocolate are interchangeable. My god. The scientific illiteracy in this country is a joke.

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