the most deadly compounds on Earth. Spike a rat’s water with 10 parts per billion—the equivalent of 7 teaspoons of dioxin dissolved in an Olympic-sized swimming pool—and there’s a 50/50 chance that the rat will die of liver cancer. Yet even tinier concentrations of dioxins fed to rats inhibit tumors. The seemingly paradoxical findings have some scientists suggesting what would have been unthink...

The phenomenon of hormesis is represented by mild stress-induced stimulation of maintenance and repair pathways resulting in beneficial effects for the cells and organisms. Anti-aging and life-prolonging effects of a wide variety of the so-called stressors, such as pro-oxidants, aldehydes, calorie restriction, irradiation, heat shock, and hypergravity, have been reported. Molecular mechanisms o...

The concept of hormesis, or low-dose U-shaped responses, is now well established in toxicology and pharmacology but requires development in medicine and therapeutics. In doing so, care must be taken to not confuse metaphorical and chemical uses of the term hormesis. Low dose, continuous adaptive responses are fundamentally different than conventional pharmacology, and they may improve the scien...

Hormesis is a concept of biphasic dose–response to different toxicological and pharmacological stimuli. According to this concept, a noxious agent at a small dose can exert a beneficial action. Among the known hormetic agents are pro-oxidants, heavy metals, heat, radiation, exercise, food restriction and different kinds of stress. All these agents are present in the environment so that the horm...

This brief commentary will argue that whether hormesis is considered in regulatory risk assessment is a matter less of science than of science policy. I will first discuss the distinction between science and science policy and their roles in regulatory risk assessment. Then I will focus on factors that influence science policy, especially as it relates to the conduct of risk assessments to info...

Free living organisms typically occur in harsh environments challenged by abiotic stresses of varying intensities. Taking ionizing radiation and caloric restriction as examples, environmental variation from benign to extreme gives a fitness-stress continuum where energetic efficiency, a measure of fitness, is inversely related to stress level. Hormesis occurs in benign regions for these example...

The effects of calorie restriction without malnutrition seem to possess many beneficial effects in numerous disease states. Recently, studies related to calorie restriction mimetics that biochemically mimic the effects of calorie restriction are also becoming increasingly popular. Both calorie restriction and calorie restriction mimetics trigger an adaptive response reminiscent of mild-stress o...

Although plant diseases can be caused by bacteria, viruses, and protists, most are caused by fungi and fungus-like oomycetes. Intensive use of fungicides with the same mode of action can lead to selection of resistant strains increasing the risk of unmanageable epidemics. In spite of the integrated use of nonchemical plant disease management strategies, agricultural productivity relies heavily ...