Flavonoids, polyphenolic compounds found in plants, have antioxidant powers that may provide important health benefits. Diets rich in flavonoids have been associated with reduced risk of a variety of diseases. However, further research is needed to determine whether flavonoids alone are responsible for these benefits rather than the whole foods that contain flavonoids. Flavonoid-rich foods include cocoa, apples, onions, cranberries, tea and red wine.
Antioxidants may protect the body’s cells from harmful free radicals from cigarette smoke and other environmental contaminants, according to the Cleveland Clinic. Free radical damage can increase LDL, or “bad” cholesterol, increasing the risk for heart disease.
Cocoa and chocolate contain a type of flavonoid called flavonols that may reduce dangerous inflammation in the arteries. A 2009 study in the “American Journal of Clinical Nutrition” found that daily consumption of skim milk with 40 g of unsweetened cocoa powder reduced levels of adhesion molecules in human subjects. Adhesion molecules can cause plaque buildup in the arteries, increasing the risk for heart disease, especially atherosclerosis, the hardening of the arteries.
Heart Disease Risk
Flavonols in cocoa may help lower blood pressure and cholesterol, helping to reduce the risk for heart disease, according to the Cleveland Clinic. Cocoa and dark chocolate may also have positive effects on blood clotting, coronary artery function and insulin sensitivity, according to Harvard Health Publications of the Harvard Medical School. Other flavonoid-rich foods that may help reduce heart disease risk include apples, onions and black tea, according to the Linus Pauling Institute at Oregon State University. However, some studies have found that increased flavonoid intake did not significantly reduce coronary heart disease risk or stroke risk, notes the Linus Pauling Institute. Further research is needed to determine the role of flavonoids and flavonoid-rich foods in heart disease risk.
Studies have found that flavonoids inhibit a variety of cancers in animals, but insufficient evidence exists to show that high flavonoid intake can reduce human cancer risk, according to the Linus Pauling Institute. However, researchers at Cornell University have found that extracts from flavonoid-rich onions provided strong anti-proliferation effects against liver and colon cancer cells.