Plant polyphenols in prevention of heart disease.

Polyphenols (PPH) are a group of chemical substances found in plants, characterized by the presence of more than one phenol unit . The largest and best studied polyphenols are the flavonoids, which include several thousand compounds. PPH are the most abundant antioxidants in human diets. Their sheer mass in the diet exceeds that of the consumed vitamins. The Mediterranean diet is rich in PPH because it contains abundant vegetables, fruits, unrefined cereals, legumes, nuts, garlic, olive oil and red wine. Locations where the Mediterranean diet prevails are known for a reduced premature cardiovascular disease (CVD) mortality. However, this geographic distinction is not entirely unique. Low CVD mortality is also present in countries with high consumption if plant food and fish, as Scandinavia, Switzerland and Austria. Putative mechanisms of the metabolic effect of PPH are related to multiple biologic functions that may have beneficial effect in the prevention of some inflammation-mediated disorders, including CVD. Naturally occurring dietary PPH can directly scavenge free oxygen radicals, adhesion molecules, and growth factor receptor genes. Thus, these polyphenolic compounds have potential therapeutic value as antioxidant and anti-inflammatory agents in CVD. PPH reduce the generation of oxidized low density lipoproteins (LDL), induce nitric oxide (NO) production, inhibit platelet aggregation and downregulate expression of proinflammatory mediators (Fig. 6, Tab. 1, Ref. 33).