Research helps maximize the health benefits of fruit smoothies.
If you’re blending a smoothie to boost your health with flavanol-rich berries, you may want to leave out the banana. New research suggests that adding banana could significantly reduce the health benefits you’re hoping to gain.
In a study published in Food and Function, scientists tested how a naturally occurring enzyme, polyphenol oxidase, affects the body’s ability to absorb flavanols. This enzyme, responsible for the browning that occurs when fruits are cut or bruised, is found in many fruits and vegetables but is especially abundant in bananas.
Bananas Slash Flavanol Uptake by 84%
The study, led by researchers at the University of California, Davis in partnership with the University of Reading, found that adding a banana to a berry smoothie reduced the absorption of flavanols by a striking 84%. For comparison, participants who took a flavanol capsule absorbed significantly more of these beneficial compounds.
Flavanols are natural compounds known to support heart and brain health. The Academy of Nutrition and Dietetics recommends a daily intake of 400–600 milligrams. A lack of flavanols, especially in older adults, has been linked to cognitive decline and poor cardiovascular function.
Gunter Kuhnle, Professor of Nutrition and Food Science at the University of Reading and co-investigator of the study said: “If you don’t consume enough flavanols, it can negatively affect cardiovascular health. In older adults, a deficiency of flavanols is also linked to cognitive decline. So, it’s clear we need them, but the question is how best to get flavanols from the food and drinks we consume.”
How Smoothie Ingredients Alter Nutrient Absorption
Lead scientist Javier Ottaviani, director of the Core Laboratory of Mars Edge, which is part of Mars, Inc., and an adjunct researcher with the Department of Nutrition at the University of California, Davis said: “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.”
Professor Kuhnle said: “Smoothies are a popular way to pack fruit and vegetables into our morning routines. We know from previous studies that flavanols can be broken down by polyphenol oxidase. The extent of the effect from adding a single banana was still very surprising – it had enough polyphenol oxidase to destroy the vast majority of flavanols found in the berries.
“Bananas may be ruled out of the morning smoothie if you want to boost your flavanol intake, but on their own, they are still great fruits an can play an important role in many healthy diets.”
Which Fruits Are Best for Flavanols?
Flavanols are found in apples, pears, blueberries, blackberries, grapes, and cocoa, which are all common smoothie ingredients. But is blitzing them up in a smoothie an effective way to get what you need?
Participants were given a smoothie with banana and berries, one with just mixed berries, or a flavanol capsule. The researchers then took blood and urine samples to measure the flavanols that actually made it through and into the participants’ body.
The researchers found that both the flavanol levels in the smoothie, and the levels absorbed by the body, were reduced when banana was included.
Professor Kuhnle said: “We still know very little about food-food and food-nutrient interactions, even though they can have a huge impact on the uptake of nutrients and bioactives like flavanols.
“Here, we could show that the uptake of flavanols can vary by more than fivefold depending on the combination of foods.
“Bananas are a great ingredient in smoothies to provide a nicer texture, but they can affect flavanol uptake.
Tips for Maximizing Flavanol Intake in Smoothies
“If you want to boost your flavanol intake with a smoothie, you should combine flavanol-rich fruits like berries with foods that have a low polyphenol oxidase activity like pineapple, oranges, mango, or yogurt.”
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
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104 Comments
After reading hundreds of studies about food, I’m going to live on air and water.
Key of success is fresh water and clean air.
Eat only one kind fruit in one time and everything will Ok.
Bananas are the ruiners of smoothies. They are known flavor bullies. They are always put in smoothies as filler. I don’t put blueberries in your banana strawberry smoothie. Why did you just put a whole banana in my peach strawberry smoothie? Of zero actual consequence to anything but now, with this brilliant article, they are confirmed double smoothie bullies. Although low on the of things that must end, stop putting bananas in every smoothie.
So are bananas good or bad for you?
I read they are bad because they’re mostly sugar and good because they contain important nitrogen.
Nutrients… not nitrogen!
as the banana ripens it turn more and more to sugar content.
Bad
Hahahaha!!! Mostly sugar. Good grief, all fruits are “mostly sugar.”. That doesn’t mean they’re bad for you. This insane obsessiveness over sugar needs to stop. There’s nothing wrong with sugar. JUST sugar might be a problem, as it doesn’t contain vitamins and minerals, but that’s it. Eat a balanced diet, get plenty of protein and carbs and minimal fat and you’ll be fine. It’s calories that are the problem, not sugar. And carbs do not make you fat. That’s an enormous myth. Fat is much more likely to be stored as fat in your body because, well, it’s fat!
I can stop putting bananas in my smoothies, I don’t want to but I will.
Avocado adds a great mild texture
Wow. I entirely agree with you. The brand Naked uses bananas in their smoothies, and the darn banana flavor overpowers the other ingredients. I think they use bananas in everything because bananas are cheaper than other ingredients and add sweetness. Nothing at all wrong with bananas! But not in everything! If I want banana flavor, I’ll just make a banana smoothie!
Anyone believing in this should research about this site (SciTechDaily) absolutely not credible….
How dare you. Bananas are the best thing to put in smoothies. Especially strawberry banana ones.
Stomach study says yum.
That’s funny but true a better look at what you really need
Thanks, I will freeze my cucumbers
Too dangerous, air is polluted and water will make you have no electrolytes
I agree, so much misinformation.. it’s unbelievable. The Internet is now not a reliable source for information. Period !
Obviously when they say don’t touch something that’s exactly what you should gravitate towards.
Me Too. This is our water and air only movement…
What about avocado?
But banana yummy
Seems like if something is good for us. The medical industy loves to tell us it’s bad. Eggs bad for us years ago and now they are a superfood. HMMMM.
I’ve never seen a sick monkey!
Except in a lab where they poison them on purpose..
When a monkey dies in a lab, they blame on their swinging lifestyle. Lol
Just
Meet the new glucose people. They just keep finding new things to change
Yeah that can happen when your curiosity drives you to explore and investigate previous assumptions. Sometimes such discoveries lead to changes in behavior. I still prefer it to previous times when people thought that everything important had already been known, and continued with self-destructive behavior like not washing their hands and thereby infecting wounds they were treating.
Instead.of freezing a banana, I will slightly freeze a cucumber
Why don’t they ever lists the studies so we can research it ourselves? Fake News for everything.
What about avocado?
C’mon Folks, all this over banana?
Either put it in your smoothie or do not. That was not the message the author was trying to convey.
JDK
Eagle, ID
But the polyphenol oxidase will help decrease or prevent kidney stones… so not having it is not exactly better
Just eat the banana at a separate time
Yes! Yes! Yes!
You’re confusing the “medical industry” with mass media who don’t know how to put research funding in the right context, or science-illiterate readers who jump into the comments before reading the whole article. “Bananas reduce flavonol uptake” is fine in the context of the many other benefits of bananas.
Everything has pros and cons. Actual scientists, researchers, and doctors know this. It’s just people like you who can’t hold more than one idea in your head at a time who get mad about being told things are “good” one day and “bad” another.
This has been known for a very long time. This is not new. This is not the media.
And full of potassium, which your body needs to function!
If the world weren’t so busy fighting against literal assaults against human rights I’d suggest that articles this poorly written, unhelpful, and outright misleading should incur legal and economic penalties for Attempted Enshitification of the Internet.
You’re an idiot
Yes. And meat has lots of protein, but we don’t put meat in smoothies. Why cantcha just eat a banana???? People have been doing it for years, even before we had blenders! The article is NOT telling us not to eat bananas, just saying that, in smoothies, bananas tend to overpower other flavors. Which is true.
How and show us how u think 🤔 that because you always just bring up unwanted stuff without proof. Anyone agree?
I find this study not only insulting 😡 but also lacking credible information 👎. #Research #Science #Facts
Too bad we don’t have something like the world wide web to look things up. You people should worry less about your diets and concern yourself with your failing intellectual capacity.
Cool story though the next study will show that we show double them.
To confirm, in a berry smoothie don’t add bananas are you ruin the benefits of flavonols from the berries.
Bananas themselves are rich in flavanols.
Next up:
Researchers warn, “Don’t Eat Bananas, They Block Flavanols!”
I use bananas in my smoothie and put berries in oatmeal or yougurt or a slice of bread with almond butter. This way I get the nutrients from the banana protein shake and the flavonoids from the fruit eaten separately.
Bananas aren’t bad, they have discovered there is a blocking action when they are combined with berries, etc.
They sure do lend their sweetness and creaminess to smoothies…but very good to know how how they block a significant amount of the nutrients from the berries! Won’t be mixing them with berries any longer. They are packed with goodness, but will be consuming them in a way to get the best nutrition.
Wondering if avocado (and avocado oil, as well?) added to a salad has the same blocking action of the vegetables in the salad. Would like to see research looking into that, as well. Would not stop consuming, but if a more efficient way to get nutrition is discovered, would take advantage of that knowledge.
Losing weight it not any indication of the state of one’s nutrition.
Calling BS. I had banana berry smoothies almost every day for two years and lost 50lbs. Berries are brain food, bananas are liver food. Read Medical Medium if yall tired of misleading articles like this.
It’s perfectly reasonable to be skeptical—here are the key reasons this finding may be over‑hyped:
1. Secondary source vs. primary research
SciTechDaily is a science news aggregator that often parrot press releases. These summaries can gloss over critical details like exact methods, sample characteristics, and funding disclosures .
2. Tiny, homogeneous sample
The core trial involved only 8 healthy men, with a follow‑up in 11 subjects. That’s far too small and narrow a group to draw broad dietary recommendations .
3. Single‑blinded crossover design
Only participants were blinded—researchers knew who got which smoothie—which can introduce conscious or unconscious bias in data collection and analysis .
4. Acute pharmacokinetic endpoint, not health outcomes
They measured the peak plasma concentration (Cₘₐₓ) of flavanol metabolites (an 84 % drop with banana vs. berries), but didn’t report total exposure (AUC) or any clinical endpoints like changes in blood pressure or oxidative markers .
5. Industry ties
The lead author heads the Mars Edge lab (Mars, Inc.), which markets flavanol‑rich products. That doesn’t invalidate the work, but it does warrant closer scrutiny of study design and data interpretation .
6. Reliance on in vitro simulations
Part of the flavanol loss was demonstrated by incubating the smoothie in simulated gastric juice (pepsin at pH 3), which can’t fully replicate the dynamics of a living stomach .
7. Narrow nutrient focus
Bananas also supply fiber, potassium, vitamin B6, vitamin C and resistant starch—nutrients with well‑documented health benefits. Discarding them just to chase flavanol peaks ignores the bigger nutritional picture .
—
Bottom line: The enzymatic browning mechanism is scientifically sound, but this single small trial—reported second‑hand—doesn’t justify ditching bananas from your smoothies. Wait for larger, more diverse studies with real‑world health endpoints before changing your blender lineup.
Sounds to me that you put the article into ChatGPT and asked it, “what are the problems with this study”. If not hallucinated, then these points do sound reasonable. But the fact remains that in-vitro there seems to be a significant effect and the precautionary principle would rather suggest ditching bananas from the mix, because the cost of doing so compared to the plausible benefit is minimal.
Brought to you by Mars Inc. The notoriously secretive candy company.
I’m in no way connected to Mars and never have been. I’m an MS level analytical chemist. I know that Mars was one of the very early adopters of greenhouse gas emission standards. They have seemingly been one of the most transparent corporations in the US. I’ve seen that they source raw materials with high levels of sustainability as well. I totally concur with Captain Obvious. Mars funded research that would not be funded by Trump’s Idiot Party.
👏🏼👏🏼👏🏼🎯
Leave my man alone..
Yes. And meat has lots of protein, but we don’t put meat in smoothies. Why cantcha just eat a banana???? People have been doing it for years, even before we had blenders! The article is NOT telling us not to eat bananas, just saying that, in smoothies, bananas tend to overpower other flavors. Which is true.
Now this is the best comment here. Thank you for the insightful information!
👏👏👏👏👏🙌🙌🙌🙌🙌👏👏👏👏👏
🤝
Maybe if you had them separately you would have been healthier. That’s what the article tells you they found through experiments.
Agree. Eat berries separately and put bananas in smoothie. Add cinnamon. Good for you too. And yummy
Cool! Someone who actually read the whole article – and has the attention span to hold onto all the concepts therein.
Every one of the numerous negative comments above clearly show that the author is missing one or both of those factors.
Misleading title. The study doesn’t state to eliminate bananas from smoothies but to not add them to berry smoothies. Banana smoothies still have merit.
Seems like anything and everything is bad for you these days. While science is more safiistcated today, I believe the real reason our foods are bad for us is how they are grown and particularly what artificial items are implemented.
Thank you
I take these “new discoveries” on nutritional health at face value. Once upon a time the “food pyramid” was what humans were told to base their diets on. “Scientists” told us to do that. Sooo check out how that’s going these days…….
Actually the Food Pyramid was developed based on food costs / availability, as well as to benefit farmers.
Recycling an almost 2 year old story.
Dumb …. fruits and veggies are good for you and if care to much about this stupid minutae, then you discourage the use of the smoothie to make downing these much more enjoyable. Ignore this. I guarantee you will survive but not live forever
Lol but bananas are a berry!
This coming from people that don’t classify ultra processed foods bad for you
Humans primates, and primates are frugivores. We’re meant to live on fresh fruit and leafy greens just like our closest relatives in nature, the bonobos. Bananas are an excellent choice for humans. Don’t listen to this ridiculous propaganda masquerading as science. Science is for sale…beware.
Jim, Your bias against science is so blatant that it is mysterious how you might justify the use of a smart phone or a computer.
People don’t seem to understand the study. It says, very generally:
– BANANAS are GOOD.
– BERRIES are GOOD.
– Bananas PLUS Berries: benefits of berries decrease.
(Their graphic is confusing / incorrect.)
Thank You. It couldn’t be laid out any clearer or nicer.
The article doesn’t say ‘Don’t eat bananas’.
There are sooo many other ways to eat bananas!….
3 Ingredient Banana Oatmeal Cookies,
Or Use 2 mashed bananas instead of the oil in a brownie mix,
Or just eat a banana!
To the other critical commentors suggesting propaganda, misleading, misinformation:
It’s good info, science is good, research is good.
Take it or leave it.
Have a wonderful day.
I already have heart issues but I’m not going to give up strawberry banana smoothies. In fact, I’ll just drink more of them because I don’t care what happens to me.
Look at it like this my duck is a banana and my nut are like berries if you suck or eat them together you get extra cream with protein in it. Now theres nothing wrong with that.
Aren’t bananas berries? Also I feel the majority of us drink smoothies because they taste good.
Aren’t bananas berries? Also I feel the majority of us drink smoothies because they taste good. 🙁
Sounds like a study done by banana haters. No way I’m making my smoothies without them. Banana is life, Banana is love, amen.
The study was made with 19 males. Maybe more study needed before banning a banana?
You tell em sport!
You tell em sport !
Well, never any bananas in my 17 ingredient smoothie; and now no avocado. I can always have guac. on toast later in the day. Thanks for the “heads-up” . (sorry ’bout the quotes) 😊
By the way: bananas are CHOCK FULL of nasyy, nasty pesticides. Go organic, please, it’s important. 😊
Wrong, the study suggests, suggest =/= show
🙂
Someone needs to brush up on their science 🙄
Well i kno this IT (such a study) DESTROYS the efforts FOR DECADES of all the thousands
and thousands who automatically tossed in increasingly ripening BANANAS to git healthy
and DO the right thing. How could anyone just KNO this was this destructive by accident?
It was a healthy thickener and taste enhancer – we thot, And that has been for DECADES!
Smoothie Shops all over Southern California Northern California and Hawaii ‘ specialized ‘
in it with No Warning – as well as even NOW how many individuals will read THIS article??
LIFE is too CRUEL sometimes . . . if U want to SURVIVE!!! as long as possible.
So they state it’s the browning enzyme in bananas and avocados that prevents flavanol uptake, but what if the smoothie is consumed as soon as it is prepared before any browning occurs?
Also they state in the article and graphic that apples contain both PPO and flavanols, then what?
I had tasted the difference in my strawberry banana smoothies, but always chalked it up to the creaminess of the banana. I’m amazed I must be able to taste the lack of flavanols, the drinks with banana taste less “nutritional”.
The classification of food has been done thousands of years before in many cultures. Ayurveda clearly states what should be eaten together and what not. But rather than including the ancient wisdom, the modern science only believes in what it has established.
Only rediscovering what is stated like this study.
It’s bananas!
Seems more like since we can’t grow bananas in the US effectively (and this administration wants a trade war) we will see a lot more propaganda against things we can’t grow or create here.
Study Shows You Should Skip Bananas in Smoothies
Fine Print: Study suggests
I’m raising the bulls*** flag as bananas are a wonderful source of fiber and potassium. It’s a known fact that scientists will agree 99 percent of the time with whoever is paying them! You just can’t trust science anymore I mean science says breathing air is unhealthy after all.
I can think of a lot of foods worse than a banana to eat.
Eat a golden banana better than regular banana or a more exotic nymph bannana.Healthier options.
Don’t listen to these studies
Years ago eggs were bad after a year they were great they say this about everything in 66 and I eat what I want and I’m not going to stop cause of this study bananas no less stop telling people things like this God never makes a bad thing
Even if this were further along in its research, if its the cutting and browning that causes the reduction in flavanols, couldn’t you just blend the banana and berries separately to stop the reaction. It sounds like theyre saying its the process of blending them together that causes the effect, so just blend the bananas separately then pour the mixes together.
This is old news. Dr. Michael Greger from nutritionfacts.org reported years ago that once the bananas start browning the effect is to reduce flavanols in the berries. The solution is easy. Buy green bananas, remove skin and freeze them, using them as needed.
However, bananas are high in sugar, so beware the risks of weight gain and prediabetes.
Whatever, i will eat it anyway
So drink a berry smoothie without a banana in it. Make sure to listen to Gwen Stefani while blending it. But then…. Eat a banana at some point afterwards? I’m so confused. What do I do with my hands? I’m just going to eat an egg McMuffin instead
Hey guys I have an idea maybe you can just leave bananas out of your smoothies to get your flavanols and then. Later on in the day at least a few hours later or the next day you have a smoothie with bananas in it .taking iron supplements is blocked by caffeine intake too so I don’t drink coffee two hours before or after my iron supplement that way I can absorb the iron .this article reminded me of the whole iron absorbtion blockage that caffeine creates
Obviously when they say don’t touch something that’s exactly what you should gravitate towards.
What a dumb article. Why do you even bother. We shall still consume banana and berries. Go and touch grass
Why is the flavanol absorption in the banana berry smoothie being compared against a flavanol capsule instead of the exact same smoothie without the bananas? A glass of orange juice is not the same as a vitamin c capsule.
I wonder if this is true for all humans or just any that have gone through puberty. It may be different for children.