Rising levels of oxidative stress occur with aging. This term describes the presence of excessive numbers of oxidative molecules, reacting with surrounding molecular machinery to cause breakage and cellular dysfunction. It is significant enough in aging for the free radical theory of aging to have arisen some decades ago, postulating that oxidative damage was the cause of aging. Alas, matters are not that simple. Persistently raised levels of oxidative stress are a downstream consequence of deeper causes, such as mitochondrial dysfunction, chronic inflammation, cellular senescence, and the like. Further, oxidative molecules do in fact serve a necessary and useful role in healthy cellular metabolism. They act as signals to spur cellular maintenance, for example, and thus small or temporary increases in oxidative stress tend to be beneficial. This is one of the mechanisms by which exercise produces health benefits.

Naked mole rats are a strange species, an outlier among rodents. They are eusocial, like some insects. They live nine times longer than similarly sized rodent species, and show few signs of aging across most of that life span. They exhibit high levels of oxidative stress, but appear near completely immune to the consequences that would appear in rats or mice given the same flood of oxidative molecules. They show the presence of senescent cells, but appear largely unaffected by that as well, which is interesting given the very prominent role played by the harmful, inflammatory secretions of senescent cells in the aging and age-related diseases of mice. Finally, naked mole rats are near immune to cancer.

Needless to say, researchers are quite interested in learning how exactly of all this is possible. Might any of the findings result in biotechnologies that can be applied to humans, to shut down cancer, or resist aging? No-one knows. My suspicion is that it will take a while to find out, and there is a good chance that altering humans to be more like naked mole rats is not a near term project - something for the latter half of the century, not the next few decades. I would say we are better off trying to repair the metabolism we have rather than building a better one, given the present state of biotechnology. It is a much more plausible goal.

The Naked Mole Rat: A Unique Example of Positive Oxidative Stress