Dietary flavonoids in atherosclerosis prevention

More in vivo studies are needed to determine conclusively whether flavonoids inhibit the growth of atherosclerotic plaques, thus reducing the risk of atherosclerosis. In vitro data are contradictory, as the doses used may not be representative of the typical dietary intake of flavonoids, and not enough in vivo data exist to make conclusive statements. Exactly which flavonoid(s) may cause therapeutic benefit remains unclear because quercetin does not appear to be systemically absorbed, and myricetin and gossypetin have the potential to increase uptake of LDL by macrophages. More pharmacokinetic studies are needed to determine the bioavailability of each major dietary flavonoid. In vitro studies have shown that flavonoids possess potent antioxidant activity, which may slow oxidative modification of LDLs. Additional studies similar to the Zutphen Elderly Study and controlled clinical studies are needed, with more accurate estimates of daily flavonoid intake to determine conclusively whether a high-flavonoid diet reduces the rate of atherosclerosis. Until those studies are completed, consuming flavonoids cannot be recommended as a means to reduce the risk of atherosclerosis. Instead, one should focus on limiting the amount of saturated fats in the diet, smoking cessation, and participating in physical exercise to reduce risk of atherosclerosis.