Hormetic Interventions in Aging

Single or multiple exposure to low doses of potentially harmful agents can have a variety of anti-aging and longevity-extending hormetic effects. These hormetic stressors include irradiation, physical activity, food limitation, heat, hypergravity, dietary components and reactive oxygen species. Molecular mechanisms facilitating the hormetic effects are being elucidated and comprise a cascade of stress response and maintenance and repair pathways. Although the extent of immediate hormetic effects after exposure to a particular stress may only be moderate, the chain of events following initial hormesis leads to biologically amplified effects that are much larger, synergistic and pleiotropic. A consequence of hormetic amplification is an increase in overall defence capacity of cells and organisms. Therefore, healthy aging may be achieved by hormesis through mild and periodic, but not severe or chronic, physical and mental challenges and by the use of dietary hormesis incorporating mild stress-inducing molecules called hormetins. However, prescribing a practical anti-aging hormetic regimen comprising physical, chemical, dietary and psychological stressors requires detailed information akin to that needed to develop personalized medicine.