Most studies (matched populations, past and present) indicate that everything else being equal an average American pot smoker will live longer than his counterpart who does no drugs at all; with fewer wrinkles, and generally less stress thereby having fewer illnesses to upset the immune system, and being a more peaceful neighbor.
(Costa Rican and Jamaican Studies)
Definite Benefits for Marijuana Smokers
The most exhaustive study of hemp smoking in its natural setting is probably Ganja in Jamaica A Medical Anthropological Study of Chronic Marijuana Use by Vera Rubin and Lambros Comitas (1975; Mouton & Co., The Hague, Paris/Anchor Books, NY).
The Jamaican study, sponsored by the National Institute of Mental Health (NIMH) Center for Studies of Narcotic and Drug Abuse, was the first project in medical anthropology to be undertaken and is the first intensive, multi-disciplinary study of marijuana use and users to be published.
From the Jamaican Study introduction: “Despite its illegality, ganja use is pervasive, and duration and frequency are very high; it is smoked over a longer period in heavier quantities with greater THC potency than in the U.S. without deleterious social or psychological consequences. The major difference is that both use and expected behaviours are culturally conditioned and controlled by well established tradition.” “No impairment of physiological, sensory and perceptual-motor performance, tests of concept formation, abstracting ability, and cognitive style and test of memory.”