To establish the role of oxidative damage ( Table 3), it is therefore essential to be able to measure it accurately. If the oxidative damage is involved in the origin of a disease, then successful antioxidant treatment should delay or prevent the onset of that disease ( Halliwell, 1991, 2002a, 2002b Galli et al., 2002 Steinberg & Witztum, 2002). If oxidative damage contributes significantly to disease pathology ( Table 3 lists the criteria needed to establish this), then actions that decrease it should be therapeutically beneficial ( Halliwell, 2001 Lee et al., 2002a Liu et al., 2003). Other diseases in which oxidative damage has been implicated include cancer, atherosclerosis, other neurodegenerative diseases and diabetes ( Hagen et al., 1994 Chowienczyk et al., 2000 Halliwell, 2000a, 2001, 2002a, 2002b Parthasarathy et al., 2000).

For example, many studies have shown increased oxidative damage to all the major classes of biomolecules in the brains of Alzheimer's patients ( Halliwell, 2001 Butterfield, 2002 Liu et al., 2003).

Free radicals and other ‘reactive oxygen (ROS)/nitrogen/chlorine species' (for an explanation of these terms see Table 1) are widely believed to contribute to the development of several age-related diseases, and perhaps, even to the aging process itself ( Halliwell & Gutteridge, 1999 Sohal et al., 2002) by causing ‘oxidative stress' and ‘oxidative damage' (terms explained in Table 2).

Chocolate hebe chan