The Emerging Role of Flavonoid-Rich Cocoa and Chocolate in Cardiovascular Health and Disease

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Dietary flavonoids and their potential role in the prevention of cardiovascular disease have gained recent scientific and medical interest due to their antioxidant properties. 1 Oxidative stress due to excess free radicals or reactive oxygen species (ROS) is associated with a number of cardiovascular risk factors, i.e., hypertension, dyslipidemias, diabetes, smoking. Cellular DNA, proteins, and lipids are susceptible to ROS attack which can result in damage to cell membranes and organelles. Tissue damage and pathophysiological processes eventually ensue. The oxidative modification of low density lipoprotein (LDL) due to oxidative stress is believed to be a major contributing factor in atherosclerosis. Thus, dietary flavonoids due to their antioxidant properties may be beneficial in cardiovascular health and disease.


Epidemiological studies suggest flavonoid-rich diets high in fruits and/or vegetables reduce the risk of coronary heart disease. (2-4) A recent meta-analysis of seven prospective cohort studies with 105,000 individuals indicated that high dietary intake of flavonoids from a small number of fruits and vegetables, tea and red wine are inversely associated with coronary heart disease risk. 5 The antioxidant properties of flavonoids are related to their structure, two aromatic rings on the ends bound by an oxygenated heterocycle in the middle which promote free radical scavenging. The flavonoids as a subclass of polyphenols, are ubiquitous micronutrients derived from plants, primarily fruits and vegetables. There are more than 5,000 flavonoids identified and the six major flavonoid categories include: flavanols, flavanones, flavones, isoflavones, flavonols, and anthocyanidins. 6

The various subclasses are listed below and include typical foods or beverages with a substantial content of flavonoids; flavanol (catechin, epicatechin-chocolate, tea, red wine, beans, apricot, cherry, grape, peach, blackberry, apple), flavanones (hesperetin, naringenin, eriodictyol-citrus fruits and juices), flavones (apigenin, luteolin-parsley, celery), isoflavones (daidzein, genisteinsoy products), flavonols (quercetin, kaempferol, myricetin-onions, kale, broccoli, tomato, blueberry, apples, tea, red wine), anthocyanidins (cyanidin, pelargonidin, peonidin, delphinidin, malvidinblueberry, black grape, cherry, blackberry, black currant, rhubarb, strawberry, red wine, plum, red cabbage). 7,8 Interestingly, cocoa and chocolate contain both a high quantity and quality of antioxidant flavonoids, even exceeding black and green tea as well as red wine. 9,10 Dark chocolate ranks the highest of top antioxidant foods as indicated by the oxygen radical absorbance capacity (ORAC) measurement (Figure 1).11,12

Figure 1: Antioxidant Foods rated by
ORAC (Oxygen Radical Absorbance Capacity)





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