The 1 Common Fruit You Should Stop Putting In Your Smoothies

You're probably best leaving it in the fruit bowl.
Kseniya Ovchinnikova via Getty Images

You really can’t beat a smoothie when it comes to an easy way to get your five-a-day in (or you’re just after a really low effort snack).

However, it turns out that we’re all making a mistake when it comes to what we’re putting in them – and it’s affecting our smoothies’ health benefits.

Yup, despite bananas being a brilliant bulking fruit for our smoothies, adding them to your drink can actually affect how well your body absorbs heart-healthy flavanols.

Let us explain. Flavanols are a group of bioactive compounds that are good for your heart and cognitive health. They’re naturally found in apples, pears, blueberries, blackberries and grapes – all of which we commonly throw into our smoothies.

Researchers from the University of California, Davis found that the enzyme polyphenol oxidase (PPO) which is found in certain fruits like bananas can reduce the absorption of heart-healthy flavanols, especially when combined with flavanol-rich ingredients like berries.

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.”

When your banana or apple rapidly turns brown when you peel or cut it, you can thank PPO. Browning occurs when the food containing that enzyme is exposed to air, cut, or bruised.

“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,” said lead author Javier Ottaviani.

“This highlights how food preparation and combinations can affect the absorption of dietary compounds in foods.”

So what do we add instead of our beloved bananas?

“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 yoghurt,” Professer Kuhnle adds.