Hormetins as Drugs for Healthy Aging
A promising strategy to slow down aging and to prevent or delay the onset of age-related diseases is that of repeated mild stress-induced hormesis. Any condition that causes low level damage in cells and leads to the activation of one or more stress response defence pathways is a potential hormetin. Physical, nutritional and mental hormetins initiate cellular stress responses and strengthen the homeodynamic space that determines the health and survival of an individual. Exercise, heat and irradiation are examples of physical hormetins, which activate heat shock-, DNA repair- and anti-oxidative-responses. Several non-nutritional chemical components in the food, such as flavonoids and polyphenols present in spices, herbs and other sources, are examples of nutritional hormetins, which induce anti-oxidative and anti-inflammatory stress responses. Calorie restriction and intermittent fasting are also hormetins, which activate the autophagic and sirtuin-mediated stress responses. Intense brain activity and focussed attention comprise mental hormetins, which also induce various stress responses. A successful strategy for discovering novel hormetins involves elucidating multiple stress responses of normal cells in culture. This requires establishing immediate and delayed stress response profiles, followed by cell type-specific functional assays, after exposure to natural or synthetic compounds and mixtures. A combination of physical and nutritional hormetins, combined with mental hormetins, can be the drugs for maintaining, improving and recovering health during aging.