I thought I'd draw your attention to a couple of good posts on hormesis over at Ouroboros, a topic favored in that part of our community. It turns out that a little of a bad thing can improve the functioning of your biological systems over time:
Small doses of 'stressors' normally considered dangerous to health can actually boost the body's self-repair system, and as a side-effect preserve youth, experts believe.
How might hormesis - the protective effect of low-dose or acute stress against higher-dose or chronic stress - work at the molecular level? One possibility is that the mild "priming" stress tones up the protective actions of stress responses: a hit of peroxide, for example, might accelerate expression of antioxidant enzymes like superoxide dismutase, protecting the cell against a future oxidative wallop. To the extent that chronic stresses can be risk factors for age-related decline in cellular function, hormetic stress might protect the cell against such long-term grinding damage, and ultimately against aging itself.
Compounds that protect against stress and aging might therefore function in a hormetic manner - either by literally stressing cells or by "simulating" stress, i.e., inducing protective stress responses without actually causing even short-term acute damage.
Hormesis in aging is represented by mild stress-induced stimulation of protective mechanisms in cells and organisms resulting in biologically beneficial effects. Single or multiple exposure to low doses of otherwise harmful agents, such as irradiation, food limitation, heat stress, hypergravity, reactive oxygen species and other free radicals have a variety of anti-aging and longevity-extending hormetic effects. Detailed molecular mechanisms that bring about the hormetic effects are being increasingly understood, and comprise a cascade of stress response and other pathways of maintenance and repair.
As for so much of what we could do with our biology today, the plausible level of beneficial effects produced by a hypothetical program of evaluated, controlled hormesis are far outweighed by the plausible level of benefits from regenerative medicine or SENS-like biochemical repair technologies of the decades ahead.
It makes sense to take care of your health today, but we're going to age, suffer and and die on a similar time frame to our grandparents if we don't support and embrace radical advances in medical technology and aging research.