Flavonoids are one group of phytochemicals found naturally in red wine, tea, cocoa, soy, citrus fruits, berries, apples, onions and pulses (dried beans, peas and lentils). There are thousands of different flavonoids found in many different foods. For example, there are catechins in tea, flavanols in cocoa and isoflavones in soy. Research shows a variety of flavonoids may be beneficial for your heart health.
Flavonoids act as a shield in plants to protect against toxins and to help repair damage. It is thought that when we eat flavonoids, they act similarly within the body. As antioxidants, they help prevent damage from free radicals that can build up during normal body processes, such as breathing. When flavonoids prevent free radicals from building up, oxidation of "bad" lipoprotein (LDL) cholesterol decreases, which prevents atherosclerosis, or plaque formation within the walls of the arteries. Flavonoids also appear to help prevent blood clotting, lower blood pressure, lower cholesterol, decrease inflammation and help with insulin sensitivity. Thus, although more research is needed, eating a variety of foods rich in flavonoids may lower your risk of heart disease.