Adding a banana to your smoothie can reduce ‘heart-healthy’ flavanol absorption by 84%

Smoothies are a super convenient option for getting healthy nutrients on the go, but a new study has found that adding a banana can reduce the body’s absorption of flavanols by 84%. So should bananas be banned from your smoothies? It all depends on your goals, says science. Research published in the Royal Society of Chemistry Food and function magazinein search of the best combination of fruits for your smoothie, found that adding banana significantly reduces the levels of heart-healthy flavonoids, leading scientists from the University of California, David, conclude that putting certain ingredients together can positively or negatively impact the health-promoting effects of your beloved smoothie. Evidently, it all comes down to an enzyme called polyphenol oxidase and how it interacts with flavanols, the bioactive compounds that benefit the heart and brain. Polyphenol oxidase, or PPO, can be seen when it reacts with the air and turns the skin and flesh of the fruit brown.

“We tried to understand on a very practical level how regular diet and food preparation, such as a banana-based smoothie, can influence the availability of flavanols that need to be absorbed after ingestion,” says the study’s lead author, Javier Ottaviani.

How was the research conducted?

The researchers had the participants drink a smoothie made with a banana – naturally rich in PPO – and a second smoothie made with mixed berries. Individuals also received a flavonoid capsule as a control. Blood and urine samples were then analyzed to determine the presence of flavanols in the body.

What were the results?

The effects of the banana were significant, contributing to up to 84% lower levels of flavonoids in the body. “We were really surprised to see how quickly adding a single banana reduced the flavanol levels in the smoothie and the levels of flavanol absorbed into the body,” says Ottaviani. “This highlights how food preparation and combinations can influence the absorption of nutritional components in foods.”

So should bananas be banned from smoothies? It’s a matter of nutritional goals, Ottaviani explained. Bananas offer a variety of other benefits, including heart-healthy potassium, fiber that aids digestion, and energy-boosting carbohydrates and vitamins. But for those who want to use their smoothie to boost flavanols, other options may work better. To choose the right fruit combination, Ottaviani says that reaching the recommended goal of 400 to 600 milligrams of flavanols per day for cardiometabolic health involves choices such as pairing flavor-rich fruits like berries with fruits that are naturally low in PPO, such as pineapple, oranges or mango.