Flavonols: Eat, Drink, and Maybe Live Longer

The analyses of the NHANES study on flavonols and mortality did more than just look at a class of phytonutrients; researchers also looked at the individual flavonols and how they impacted mortality. A little background first.

Flavonoids

Flavonoids are a group of phytonutrients made up of six classes of nutrients. They are flavan-3-ols, flavones, flavanones, anthocyanidins, and the previously mentioned flavonols. Each of those classes are made up of individual phytonutrients. Flavonols have four primary phytonutrients in its class: quercetin, kaempferol, myricetin, and isorhamnetin. We’ll skip the rest of the individual phytonutrients in the other classes because they weren’t part of the study.

The researchers examined the reduction in mortality for each flavonol phytonutrient. When comparing the first quartile (lowest) with the fourth quartile (highest) intake, not every phytonutrient reduced the mortality from all conditions. In other words, the overall reduction in mortality was greatest when looking at total flavonol intake, not in any single phytonutrient. Too often research focuses on single phytonutrients as potential treatments of conditions and diseases, so it’s great to see a study that looks at total intake of a class of nutrients.

Absorption

As mentioned, flavonols are one part of the flavonoids. One characteristic is that they seem to be poorly absorbed. Or are they? It could be that there are unknown genetic factors that impact absorption and/or utilization of those nutrients. It may be that when isolated from a plant, the absorption is interfered with in some way that’s not apparent. It may be that the microbiome has a role to play in absorption.

What is most likely is that when eaten or drunk in its natural or prepared state, it is the interaction of all the flavonols that help absorption. Or it may be the combinations of flavonoids found in specific foods that work together for absorption.

What foods have the highest flavonol content? When looking at mg/100 grams, raw onions, cooked onions, apples with the peel, brewed black decaf tea, and brewed black tea top the list. When looking at the top three consumed? Onions, black tea, and apples top the list, but beer comes in fourth place. While the amount per 100 grams is low, we consume a lot of it.

The Bottom Line

At the end of the day, the most important thing to know is that we have to consume flavonols to get the benefits. In reality, your mama was right: eat your fruits and vegetables. They’re good for you. And if you chase them down with a beer, that’s probably okay as well.

What are you prepared to do today?

        Dr. Chet

Reference: Nature Reports. 2024. https://doi.org/10.1038/s41598-024-55145-y2. Arch