AHS18

What explains the modern pandemics of obesity, diabetes, cardiovascular disease, autoimmunity, asthma and cancer—and also depression, anxiety and addiction? Is contemporary life too stressful? While chronic, excessive exposure to stressors such as anti-nutrients, toxins, UV, or psychological stress can cause illness, so can insufficient physical challenge. Hormesis -- beneficial stress -- activates endogenous defense, repair and adaptive mechanisms, thereby improving health, fitness and resilience. The hardier lives of our ancestors were indeed protective against illness. I will examine the biological mechanisms behind four main types of hormesis: (1) structural remodeling of tissues and organs, such as bone, muscle and the eye, in response to activity; (2) immunity and detoxification by exposures that train endogenous defenses; (3) metabolic adaptation in response to diet, exercise, cold exposure and hypoxia; and (4) psychological resilience against depression, anxiety and addiction, by challenges that re-sensitize receptors We are suffering from a deficiency of hormesis!