Does overexpression of Cu,Zn-SOD extend life span in Drosophila melanogaster?

The argument is presented here that, while there exists considerable correlative evidence supporting the oxidative stress hypothesis of aging, key experiments to test this hypothesis using Drosophila transgenics overexpressing Cu,Zn-SOD fall short in providing validation. In particular, significant life span extensions tend to be observed when the backgrounds of the control flies are relatively short-lived, suggesting that bolstering antioxidative defenses is only effective in compromised genetic backgrounds. Other shortcomings of the transgenic approaches adopted to date will be summarized.