Flavonoids are plant secondary metabolites, present in all terrestrial vascular plants (1):
- flavonoids are defined chemically as substances composed of a common phenylchromanone structure
- all flavonoids share a common chemical structure: C6-C3-C6
- flavonoids can be further distinguished: flavonols, flavones, isoflavones, flavanones, anthocyanidins, and flavanols
- flavanols (also called flavan-3-ols) have attracted particular interest because they can be found in high concentrations in certain fruits and vegetables. In the context of human nutrition, certain teas, grape juice, wine, various berries, and especially cocoa represent noteworthy sources (2)
- a prospective study in 34 489 postmenopausal women with a 16-year follow-up in the Iowa Women's Health Study who were free of cardiovascular disease found that foods rich in flavonoids were associated with a decreased risk of death caused by coronary heart disease
- there is epidemiological data suggesting reduced cancer risk associated with high flavonoid intake
Foods containing flavonoids include (1)
- red berries, tea, soy products, red wine, broccoli, grapes/grape juice, dark chocolate, tomato, apples (with peel), red cabbage, plums, citrus fruits, onions, kale, cherry
Cocoa/chocolate and cardiovascular health (2)
- epidemiological data demonstrate that regular dietary intake of plant-derived foods and beverages reduces the risk of coronary heart disease and stroke
- among many ingredients, cocoa might be an important mediator. Indeed, recent research demonstrates a beneficial effect of cocoa on blood pressure, insulin resistance, and vascular and platelet function
- although still debated, a range of potential mechanisms through which cocoa might exert its benefits on cardiovascular health have been proposed, including activation of nitric oxide and antioxidant and antiinflammatory effects
- important to strictly differentiate between the natural product cacao and the processed product chocolate, which refers to the combination of cocoa, sugar, and eventually milk and other ingredients into a solid food product. Many of the health effects of cocoa and its contents may not be applicable to chocolate
- beneficial effects of cacao are most likely due to an increased bioavailability of nitric oxide (an antioxidant). This may explain the improvement in endothelial function, the reduction in platelet function, and the potentially beneficial effects on blood pressure, insulin resistance, and blood lipids
- but...although many positive effects of chocolate and its ingredients have been documented in the cardiovascular system, precautions in its use are mandatory. Indeed, the high caloric load of commercially available chocolate (about 500 kcal/100 g) may induce weight gain, a risk factor for hypertension, dyslipidemia, and diabetes
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