Hormesis and intervention of aging

The concept of hormesis has recently been introduced into the gerontological field. The tenet of this concept embraces the notion that the aging process has been evolved through the organism's physiologic adaptation to the ever‐changing stressful environmental conditions for survival. The hormetic phenomenon is exhibited by a biphasic bell‐shape curve response that is the characteristic biological reaction, rather than a linear response. The beneficial effect of hormesis is due to a mild and low stress inductive to stimulated response, while high stress resulting in inhibitory or harmful results. The adaptive response to a mild stress induces the organism's ability to maximize the metabolic efficiency to cope with a new challenging environment. Evidence strongly suggests that most of stresses under sub‐lethal levels can in fact to be beneficial for the survival of the organism, as exhibited by a growth stimulation of bacteria treated by sub‐lethal pesticides or the life‐span extension of mice by a low dose of irradiation. The anti‐aging action of calorie restriction stimulated by the mild nutritional deprivation considered being another good example of this hormetic phenomenon. For the future intervention of the aging and age‐related diseases based on hormesis concept, one could conceive experimental models in which the endogenous defense systems and certain immune components may be strengthened by selective stimulatory measures. In this review, discussion is presented for further development of this hormetic concept on the premise as the potential anti‐aging strategies.