Blending a fruit smoothie with your breakfast or midday snack is a convenient (and delicious) way to boost your nutritional intake.
Whole fruits and vegetables provide vitamins, minerals, and fiber, as well as a myriad of antioxidants and anti-inflammatory phytochemicals.
But if your favorite smoothie combines bananas and berries, you might not be getting as much nutritional value as you think.
That’s according to a new study from the University of California, Davis. It appears that certain fruits (and vegetables) can reduce the flavanol content of your smoothie and the amount your body absorbs.
Is your diet missing these 25 longevity-promoting foods?
Natural enemy of flavanols
Flavanols belong to a category of plant compounds called polyphenols, which are the largest and most studied group of phytochemicals.
Flavanols are found in apples, blackberries, blueberries, sweet cherries, grapes, plums, strawberries, raspberries, nectarines, peaches, and pears. It is also abundant in green tea, black tea, cocoa, pinto beans, kidney beans, hazelnuts, and pecans.
Higher intakes of flavanols have been shown to improve memory and cardiovascular health. The American Academy of Nutrition and Dietetics recommends a daily intake of 400 to 600 mg of flavanols, based largely on evidence that flavanols help improve cholesterol, triglycerides, blood sugar levels, and blood pressure.
It turns out that some fruits and vegetables are high in an enzyme called polyphenol oxidase (PPO), which breaks down flavanols. The activity of PPO varies greatly depending on the type and variety of fruits and vegetables.
PPO is an enzyme that causes certain produce to brown when exposed to air (e.g., sliced apples, peeled bananas), cut, or bruised.
new discovery
The study, published last month in Food and Function, investigated whether consuming smoothies made with different PPO-containing fruits affected the amount of flavanols available to the body.
To do so, the researchers first asked eight healthy men between the ages of 25 and 60 to drink two types of freshly prepared smoothies.
One smoothie was made with bananas, which have very high PPO activity. The other is made with mixed berries (blueberries, blackberries, strawberries, raspberries) that are high in flavanols and low in PPO activity.
A standardized flavanol extract was added to each smoothie to equalize the flavanol content.
In addition to the smoothie test, participants took the same standardized flavanol extract as a supplement with a glass of milk (control intervention).
Are smoothies healthy for breakfast?
The three tests were performed at a research facility at least six days apart. Blood samples were taken every hour for 6 hours after consuming the smoothie and flavanol supplement.
Consumption of a banana smoothie with high PPO activity significantly reduced plasma (blood) flavanol levels compared with consumption of a mixed berry smoothie with low PPO activity.
Plasma flavanols were reduced by 84 percent after volunteers drank a banana smoothie compared to after taking a flavanol supplement with milk (e.g., no banana).
Researchers found that adding one banana to a smoothie caused a rapid decrease in flavanol content within an hour of preparation.
In the second study, 11 volunteers consumed a flavanol-containing beverage and a blended banana beverage separately and at the same time, alternating sips of each beverage. This ensured that the flavanols did not come into contact with the banana PPO enzyme before participants drank the smoothie.
The researchers observed that the degradation of flavanols by PPO also occurred during digestion.
I thought bananas were good for my health. Why does the trainer tell me it’s bad?
Impact on meals, points
These new findings suggest that making smoothies with fruits with high PPO activity may reduce the flavanol content in the glass and be digested in the stomach.
This controlled study is not without limitations, including the small sample size.
Nevertheless, the reaction of the enzyme PPO with flavanols and other polyphenols has been well known for decades.
“While it would be great to see these results replicated in a larger population, we We believe that our findings are generalizable and consistent with current scientific knowledge.” within this area. “
7 ways to reset your diet to get back to work
The findings of this study suggest that we need to consider not only what types of foods we should eat to increase our intake of flavanols, but also how we prepare and consume these foods to maximize their nutritional value. It is emphasized that there is.
So if you’re trying to reach your daily flavanol goal of 400 to 600 mg, you may want to reconsider the combination of fruits and vegetables you mix in your smoothies.
Consider pairing flavanol-rich fruits (such as berries, cherries, grapes, and peaches) with foods that are low in PPO activity, such as pineapple, mango, orange, and kale.
Save the potassium-rich bananas for flavanol-rich fruit-free smoothies.
Leslie Beck, a Toronto-based dietitian in private practice, is Medcan’s Director of Food and Nutrition. Follow her on Twitter @LeslieBeck
