homehome Home chatchat Notifications


Here's why you probably shouldn't add bananas to your smoothie

Bananas in smoothies are not bad. But if you mix them with specific berries, you can have diminishing returns.

Fermin Koop
August 30, 2023 @ 10:54 am

share Share

Smoothies are a popular choice for a speedy breakfast or a nourishing snack. They’re also a convenient way to incorporate more fruits and vegetables into our diet. But while the individual fruits in smoothies are well-studied (and are good for you), the combination of fruits is less studied.

In a new study, scientists found that adding bananas to a berry smoothy reduces the flavanols, a group of bioactive compounds good for your health, by 84%. This doesn’t mean that bananas make for bad smoothies, but it hints that ideally, you wouldn’t mix bananas and fruits with flavanols.

smoothie berries and bananas
Image credits: Flickr / Gogatsby.

Flavanol-rich fruits typically include apples, grapes, pears, tea, cocoa, and berries. We should first say that there’s more to healthy nutrition than flavanols. This is just one component that makes berries healthy, there are plenty of other things to consider. But if you want to optimize your nutrition, it’s something you can consider.

Optimizing smoothies

Researchers used smoothies to test how different levels of polyphenol oxidase (an enzyme found in many fruits and vegetables) affects the absorption of flavanols by the body. Flavanos are a natural compound commonly found in foods and drinks that can reduce inflammation and protect your vascular (blood system).

We should be consuming between 400 and 600 milligrams of flavanols per day. A diet low in flavanols has been linked by previous studies to age-related memory loss.

“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,” Gunter Kuhnle, one of the study authors, said in a news release.

This is where bananas come in.

The right smoothie

Image via Unsplash.

When we peel a banana or cut an apple, the fruit turns brown very fast. This happens because of polyphenol oxidase (PPO), an enzyme naturally present in those foods. In their study, the researchers wanted to know whether drinking a smoothie made with different fruits containing PPO affected the amount of flavanols available to the body.

To find out, they gave volunteers a smoothie with banana and berries, a smoothie just with berries, or just a flavanol capsule by itself (the control group). The researchers then took blood and urine samples to measure how many flavanols were present after taking the smoothie or capsule. They found flavanol levels were reduced when bananas were included.

“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,” Javier Ottaviani, study author, said in a news release. “This highlights how food preparation and combinations can affect the absorption of dietary compounds in foods.”

The researchers said that people who are trying to consume flavanols should consider making smoothies by combining flavanol-rich fruits such as berries, pineapple, and oranges. The findings don’t mean bananas are not a good fruit to eat alone or in smoothies, they clarified, but bananas may affect flavanol update very significantly. It is further worth noting that the study was conducted among a relatively small sample of people, and only men, so effects may be different depending on the person.

Next, they hope their study can lead others to look at how other foods are prepared and the effect of flavanols. For example, Ottaviani said tea is a big source of flavanols, and depending on how it’s prepared, a different amount of flavanols would be available for absorption. “This is certainly an area that deserves more attention,” he added.

The bottom line: if you really want to optimize your smoothie, put the berries in and save the banana for later. It’ll increase your flavanol intake.

Smoothie recipes that don’t mix bananas and flavanols

There are so many fruits and other ingredients out there that you shouldn’t really run out of ideas anytime soon. But just in case you are struggling with creativity, here are some ideas to show you can do a million smoothies without mixing bananas and flavanols.

Mango Avocado Smoothie

  • Ingredients:
    • 1 ripe avocado
    • 1 cup mango chunks (fresh or frozen)
    • 1 cup spinach or kale
    • 1 cup almond milk or coconut milk
    • 1 tablespoon honey or agave syrup (optional)
    • Ice cubes (optional)

Peach Oatmeal Smoothie

  • Ingredients:
    • 2 ripe peaches, sliced
    • 1/2 cup rolled oats
    • 1 cup Greek yogurt (plain or vanilla)
    • 1 cup almond milk
    • A pinch of cinnamon
    • Honey to taste (optional)

Tropical Coconut Smoothie

  • Ingredients:
    • 1 cup pineapple chunks
    • 1 cup coconut milk
    • 1/2 cup Greek yogurt
    • 1/2 cup ice
    • 1 tablespoon chia seeds (optional)

Carrot Ginger Smoothie

  • Ingredients:
    • 2 large carrots, peeled and chopped
    • 1 inch fresh ginger, peeled
    • 1 cup orange juice
    • 1/2 cup plain Greek yogurt
    • Honey to taste (optional)
    • Ice cubes (optional)

Dark Chocolate and Cherry Smoothie

  • Ingredients:
    • 1 cup frozen cherries
    • 1-2 tablespoons dark chocolate chips or cocoa powder
    • 1 cup almond milk or coconut milk
    • 1/2 cup Greek yogurt or coconut yogurt
    • A drizzle of honey or maple syrup (optional)
    • Ice cubes (optional)

Green Tea and Grape Smoothie

  • Ingredients:
    • 1 cup green grapes
    • 1 cup brewed green tea (cooled)
    • 1/2 cup cucumber slices
    • 1/2 cup spinach or kale
    • A few mint leaves
    • Honey or agave syrup to taste (optional)
    • Ice cubes (optional)

The study was published in the journal Food & Function.

share Share

Why do some people like the smell of their own farts?

Farts stink. Unless they're yours, apparently.

Ghastly Gourmet: 7 unconventional Halloween dishes from around the globe

This year, besides pumpkin pie, you can try adding some international flavor to your Halloween dinner.

Carrots were originally purple, not orange. Here's what happened

For thousands of years, carrots were purple or yellow. Then in the 16th century, Dutch farmers came into the picture.

How to tell the difference between celiac disease and gluten intolerance

Don't diagnose yourself, take it to the doctor.

Is vitamin water good for you?

Vitamin water isn't what you think. Mostly, it is just another way to sell bottled water with greater profit margins.

Is oat milk good for you? Here's what the science says

Oat milk doesn't just taste good, it's a healthy alternative to cow milk.

What are the most addictive foods, according to science

Delve into the world of addictive foods and uncover the truth behind our cravings.

Who invented ice cream? A sweet journey through history

Ice cream went through a wild journey that started more than 2,500 years ago.

Is Almond Milk Good for You?

Almond milk is a healthy dairy substitute with nutrients and suitability for various dietary needs.

Is Soy Milk Good for You? Milk ain't what it used to be

Soy has a bad rep, but despite what you may have heard, soy milk is good for you. Here's what you need to now.