Flavonoids are the natural chemical compounds that give plants their bright colors. Research has shown that, when eaten, many flavonoids have antioxidant properties and they may therefore offer protection against cell damage. Flavonoid antioxidants are found in many commonly eaten foods. Good sources of flavonoid antioxidants include fruits, especially berries, onions, and some green vegetables. Tea, wine, beer, and cocoa are also good sources of flavonoid antioxidants.
Many fruits contain a significant amount of flavonoid antioxidants. As flavonoids contribute to plants’ bright hues, it is perhaps no surprise that richly colored fruits such as blueberries and raspberries are among the best sources of these compounds. Flavonoid antioxidants can also be found in other fruits, such as apples. It should be noted that flavonoids are often concentrated in a fruit’s skin, and that the fruit’s skin should thus be eaten along with its flesh for maximum flavonoid intake.
Onions are an excellent source of flavonoid antioxidants. As with fruits, the depth of an onion’s color seems to be directly related to its flavonoid content. Thus, a red onion tends to contain more flavonoids than a yellow one.
Some green vegetables, such as broccoli and cabbage, also contain flavonoid antioxidants. It is important to note, however, that cooking vegetables for long time periods can diminish their flavonoid content, along with their percentages of other health-boosting vitamins and nutrients. Therefore, care should be taken to avoid overcooking vegetables. As a basic guideline, some nutritionists recommend that vegetables should be removed from a heat source before their color begins to grow dull.
A number of common beverages also contain flavonoids with antioxidant properties. Chief among these are green and black teas as well as red wine. Hops also contain antioxidant flavonoids, making beer a good source of these compounds. As excessive alcohol consumption can lead to intoxication, organ damage, and chemical dependency, however, it is recommended that both wine and beer should be consumed in moderation.
Finally, chocolate lovers may be delighted to learn that cocoa contains flavonoid antioxidants. Some research has suggested that the milk contained in many types of chocolate may interfere with flavonoids’ antioxidant properties, however. Therefore, it is believed that only dark chocolate products with a cocoa content of approximately 70 percent or higher truly offer a significant antioxidant benefit. Unfortunately, many people dislike products with such high concentrations of cocoa, as they tend to be quite bitter in taste.