[Determination of the plasma global antioxidant capacity: a critical review].

With respect to prevention of cardiovascular diseases and cancers, the healthcare professionals are more and more interested in the blood determination of antioxidants (vitamins C and E, carotenoids, glutathione, ubiquinone, antioxidant enzymes). The major problem of these analysis is their elevated cost. At the request of the healthcare professionals, the laboratories of clinical biology suggest the measurement of the plasma global antioxidant capacity (GAC) as a replacement of the individual determination of all these antioxidants. The present review shows that such a test presents a large number of gaps, the major one being that it essentially reflects the plasma concentration of uric acid and proteins. On basis of nine arguments, we show that the measurement of the plasma GAC cannot be considered as an in vivo marker of oxidative stress nor lead to the prescription antioxidant complement.