Flavonoids

Flavonoids are abundant in many plant-based foods, particularly berries, apples, citrus fruits, onions, and dark chocolate. Tea, especially green and black varieties, along with red wine, are also highly significant sources of these polyphenols.

Scientists broadly categorize dietary flavonoids into six major subclasses. These include flavonols (like quercetin), flavones, flavanones, flavan-3-ols (like catechins in tea), anthocyanins, and isoflavones (found heavily in soy).

Flavonoids neutralize free radicals by directly scavenging reactive oxygen species (ROS) before they can damage cellular DNA and lipids. They also help chelate transition metals like iron and copper, preventing these metals from catalyzing further oxidative reactions.

The terms are often confused, but flavonoids are the broad overarching family of plant polyphenols, while flavanols (specifically flavan-3-ols) are just one specific subclass within that family. Flavanols are the specific compounds found in high concentrations in cocoa and green tea leaves.