Health Advice



Smoothing out smoothies' nutritional benefits

By Michael Roizen, M.D. on

Some sources say that the smoothie was developed by a young man named Steven Kuhnau who was lactose intolerant. Since he couldn't have milkshakes, he concocted a frosty mixture of fruit, ice and other ingredients. It was such a taste sensation that he went on to launch Smoothie King in 1973.

Fast forward 50 years. We now know that one of the best health benefits of a smoothie is the super-dose of flavanols you get from berries, grapes, pineapple, oranges, mango and even cocoa. Flavanols are polyphenols that offer anticancer, antioxidant, anti-inflammatory, and antiviral benefits, as well as protection for your nerves and heart.

But new nutritional info also reveals that adding a banana to that blended mixture interferes with your body's ability to absorb the flavanols. According to a study published in the journal Food and Function, there is a high level of an enzyme called polyphenol oxidase, or PPO, in bananas (and beet greens) that blocks the flavanols. People eating a banana and berry smoothie have 84% fewer flavanols in their body than those downing a smoothie made with only flavanol-rich fruits.

The science of food combinations and interactions is relatively new, but it provides valuable insights in how to maximize your nutrition. For example, we also know that combining carrots and cooked tomatoes with fat in EVOO, avocados and nuts allows your body to absorb the anti-cancer, heart- and vision-healthy carotenoids they contain. For more information on how a carefully crafted plant-based diet can make your ActualAge younger, check out


Health pioneer Michael Roizen, M.D., is chief wellness officer emeritus at the Cleveland Clinic and author of four No. 1 New York Times bestsellers. Check out his latest, "The Great Age Reboot: Cracking the Longevity Code for a Younger Tomorrow," and find out more at Email your health and wellness questions to Dr. Mike at

(c)2023 Michael Roizen, M.D.

Distributed by King Features Syndicate, Inc.

(c) 2023 Michael Roizen, M.D. Distributed by King Features Syndicate, Inc.




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