Purpose of review: Oxidative damage is involved in cardiovascular diseases. Intervention with α-tocopherol, ascorbic acid and β-carotene does not appear to reduce pathogenesis. The purpose of this review is to describe alternative antioxidant mechanisms that may be involved.
Recent findings: Antioxidants with different chemical properties may recharge each other in an antioxidant network. The total antioxidant content of dietary plants may therefore be a useful tool for testing the 'antioxidant network' hypothesis. Several berries, fruits, nuts, seeds, vegetables, drinks and spices have been found to be high in total antioxidants. Initial studies in animals and humans are supportive as to the beneficial effects of dietary plants rich in total antioxidants. Additionally, antioxidants and other plant compounds may also improve the endogenous antioxidant defence through induction of antioxidant and phase 2 enzymes. Dietary plants rich in such compounds include broccoli, Brussel sprouts, cabbage, kale, cauliflower, carrots, onions, tomatoes, spinach and garlic.
Summary: Although initial studies have indicated that antioxidants may reduce oxidative stress, human intervention studies do not support a beneficial effect of antioxidant supplements. Further research is needed to clarify whether other plant antioxidants, plants rich in a combination of antioxidants, or plant compounds that induce the endogenous antioxidant defence can reduce pathogenesis of cardiovascular disease and other oxidative stress-related diseases.
Abbreviations α-T•: α-tocopheroxyl radical; FRAP: ferric reducing ability of plasma; NF-κB: nuclear factor κB; ORAC: oxygen radical absorbance capacity; RNS: reactive nitrogen species; ROS: reactive oxygen species; TEAC: Trolox equivalent antioxidant capacity.