Role of Anti-Oxidants in Atherosclerosis: Epidemiological and Clinical Update

Abstract

Low density lipoprotein (LDL) oxidative modification in the vascular wall seems to be a key factor in atherosclerosis development. Oxidised LDLs might recruit monocytes and favour their transformation into foam cells through a receptor-mediated intake (scavenger pathway). Moreover oxidised LDLs show cytotoxic potential which is probably responsible for endothelial cell damage and macrophage degeneration in the atherosclerotic human plaque. Following the oxidation hypothesis of atherosclerosis the role of natural antioxidants, i.e. Vitamin C, Vitamin E and carotenoids, has been investigated in a large number of epidemiological, clinical and experimental studies. Animal studies indicate that dietary antioxidants may reduce atherosclerosis progression, and observational data in humans suggest that antioxidant vitamin ingestion is associated with reduced cardiovascular disease, but the results of randomised controlled trials are mainly disappointing. It has been suggested that natural antioxidants may be effective only in selected subgroups of patients with high levels of oxidative stress or depletion of natural antioxidant defence systems. The favourable effects shown by some studies relating antioxidant dietary intake and cardiovascular disease, may have been exerted by other chemicals present in foods. Flavonoids are the ideal candidates, since they are plentiful in foods containing antioxidant vitamins (i.e. fruits and vegetables) and are potent antioxidants. Tea and wine, rich in flavonoids, seem to have beneficial effects on multiple mechanisms involved in atherosclerosis. Future studies should probably select patients in a context of high-oxidative stress / low-antioxidant defence, to verify if antioxidants may really prove useful as therapeutic anti-atherosclerotic agents.

Effects of chronic and acute consumption of fruit- and vegetable-puree-based drinks on vasodilation, risk factors for CVD and the response as a result of theeNOSG298T polymorphism

“…These studies support the epidemiological findings that carotenoid-containing foods may be beneficial in reducing the risk of CVD (59) . However, they suggest that their mode of action may not be entirely a result of their antioxidant properties.…”

Dietary antioxidant intake and risk of an aneurysmal rupture subarachnoid hemorrhage in Japan

“…In general, dietary antioxidants may provide interactive or synergistic effects on health rather than any one food could not provide. The food groups and items selected in the present study contain a wide range of antioxidants such as flavonoids (including isoflavones and catechins), b-carotene, and vitamins C and E, and their antioxidant activity appears to be the result of a combination of those different compounds acting in a synergic and interactive manners (Jialal and Fuller, 1995;Honore et al, 1997;Bates et al, 1998;Williams and Clarkson, 1998;Wakai et al, 1999;Schutte et al, 2004;Cherubini et al, 2005).…”

Effect of honey on hepatotoxicity induced by antitubercular drugs in albino rats

“…Antioxidants can prevent cell damage due to the action of reactive oxygen species (ROS) and free radicals. 17 Honey contains a variety of falconoid and phenolic acids, which act as antioxidants, scavenging and eliminating free radicals. The researchers found that consuming more honey increased the level of polyphenolic antioxidants in the blood.…”