TakeAway | SHOULD YOU ADD A BANANA TO YOUR SMOOTHIES?

Banana Smoothie

New research now reveals why you shouldn’t add a banana to your smoothies. Disappointed? Please, don’t be.

A smoothie is a beverage made by puréeing ingredients in a blender, according to Wikipedia. A smoothie commonly has a liquid base, such as fruit juice or milk, yogurt, or ice cream. Other ingredients may be added, including fruits, vegetables, non-dairy milk, crushed ice, whey powder, or nutritional supplements.

On the other hand, a banana is an elongated, edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus Musa. In some countries, bananas used for cooking may be called "plantains", distinguishing them from dessert bananas. The fruit is variable in size, color, and firmness, but is usually elongated and curved, with soft flesh rich in starch covered with a rind, which may be green, yellow, red, purple, or brown when ripe.

Yep, smoothie and banana seem a perfect blend, isn’t it? But the thing is that adding banana as one of your ingredients for a smoothie or for just a banana smoothie is no longer advised, research says.

According to online reports from the University of California, 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.

Blueberry Smoothie

Thus, blending certain ingredients in smoothies can influence whether your body is getting a nutritional boost.

A 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.

In case you didn’t know, 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.

The common experience is when you 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.

Now check out this test tagged “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 has 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.

It was really surprising afterward 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. This highlights how food preparation and combinations can affect the absorption of dietary compounds in foods.

Recall 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. It’s advised 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.

No doubt, bananas remain a great fruit to be eaten or consumed in smoothies. Yes, you can smile now because, 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.