Hormesis and Mithridatism

Hormesis is the term for generally-favorable biological responses to low exposures to toxins and other stressors. A pollutant or toxin showing hormesis thus has the opposite effect in small doses as in large doses.

Did you know that for a while the Comanches suffered protein poisoning when they were eating almost only the meat of thin buffalo? Or that "water intoxication, also known as hyper-hydration, water poisoning, or overhydration, is a potentially fatal disturbance in brain functions that results when the normal balance of electrolytes in the body is pushed outside of safe limits by over-consumption of water." Apparently red wine in moderation can lower the rates of heart disease, while alcohol poisoning can be fatal.

Mithridates VI, King of Pontius

who gave his name to this effect.

Mithridatism is the practice of protecting oneself against a poison by gradually self-administering non-lethal amounts. Mithridatism can be used by zoo handlers, researchers, and circus artists who deal closely with venomous animals.