The Treacherous Ingredient in Healthy Dishes: Scientists Debunk a Common Myth

Your daily smoothie may be less healthy than you think — and it’s all because of one seemingly innocent ingredient. A recent study found that bananas drastically reduce the absorption of valuable antioxidants, reducing their effects by up to 84 percent.

My favorite smoothie? Banana , cocoa , avocado and oat milk . At first glance, it looks perfect: creamy consistency, velvety taste and pure health. And yet, scientists are sounding the alarm - bananas , although for years treated as a symbol of a healthy lifestyle , can drastically reduce the absorption of valuable nutrients, such as flavonols - by as much as 84 percent. Why are we talking specifically about flavonols ? Because they are responsible for a number of key benefits - from delaying the aging process to improving mental health.

Woman holding green smoothie / Unsplash, Roberto Nickson

A study published in the journal Food and Function and reported by SciTechDaily found that an enzyme in bananas — polyphenol oxidase (PPO) —acts like a saboteur in our blender jug. PPO, responsible for, among other things, darkening the fruit, breaks down flavonols before they can even enter the bloodstream.

In the experiment, participants consumed a smoothie containing fruits with high levels of PPO ( bananas ) and those with low levels of PPO ( berries ). Additionally, they took flavonols in capsules as a control group. The results were clear: the absorption of flavonols from the banana smoothie was as much as 84 percent lower than from the berry version. What's more, even separate consumption of flavonols and banana had a negative effect on their absorption.

Flavonols – a member of the polyphenol family – are powerful antioxidants . Numerous studies, including one published in the American Journal of Clinical Nutrition in 2025, have linked them to improved mental health , reduced risk of senility , and better quality of aging – especially in women. It’s an ingredient that deserves to be called the elixir of longevity in the world of wellness and anti-aging.

Instead of a banana , which, as it turns out, can work against our intentions, it is worth reaching for fruits with low polyphenol oxidase activity :

• pineapple,
• mango,
• oranges,

and also yogurt or plant milk . These ingredients not only do not neutralize the effects of flavonols, but they actually enhance them. Mixing is also a great idea:

with the addition of citrus fruits, which additionally enhance their absorption.

Berry smoothie - healthier than banana, according to researchers / Unsplash, Bakd Raw By Karolin