Well, maybe. Some things to consider here.

As I learned as a food biochemistry major at UC Davis, PPO requires oxygen to be activated. That’s why bananas and apples turn brown when cut. I did not noticed in the study whether they indicated how long the fruit had been cut and smoothies had been prepared before subjects ingested them. Ingesting a smoothie with bananas immediately after preparation may have little effect on the availability of flavanols.

It turns out that almonds have high levels of PPOs. I don’t know if that carries over to almond milk, but in the study the berry smoothies had half the amount of almond milk as the banana smoothies.

In the simulated gastric exposure experiment, they let the solutions sit for two hours. A liquid smoothie would pass through the stomach much more quickly.

I think there were just 8 subjects, with a wide range in age.

There are lots of great foods with high flavanol levels.

So enjoy your banana in your smoothie. Bottoms up!