What was done
The authors review what is known about the roles of oxidants, oxidative stresses and antioxidants in the biology of ageing.

What was learned
Reactive oxygen species (ROS) generated by the normal metabolism of animal cells create oxidative stresses in organisms that tend to shorten their life spans.  This burden of ROS is largely counteracted by "an intricate antioxidant defense system," according to the authors; and they say the components of this system "that increase resistance to stress should have anti-ageing benefits and lead to enhanced life span."

What it means
The authors indicate that much remains to be learned about these interrelated subjects.  One avenue of research that looks particularly promising to us - which we have noted periodically in the past (see the three categories under Life Span in our Subject Index) - is the role that may be played by the ongoing rise in the air's CO2 content in this regard.  There is much evidence, for example, that atmospheric CO2 enrichment helps plants withstand the ravages of all sorts of environmental stresses that raise oxidative havoc with them, and that it also stimulates modest increases in certain health-promoting antioxidants and cancer-fighting substances they produce.

Has this phenomenon had anything to do with the great lengthening of the human life span that has occurred over the past century or so, particularly via our ingesting of these plants or the medicines they produce?  No one knows for sure; but we continue to report on significant new developments in this most intriguing area of science in the hope that our musings will stimulate the research needed to answer this important question.  It would be the epitome of irony, for example, to discover several years after having made Herculean efforts to dramatically reduce CO2 emissions that those very emissions were the cause of our increased longevity!