However, some people who have early-onset Alzheimer's don't have mutations in these three genes. That suggests that this early-onset form of Alzheimer's disease is linked to other genetic mutations that haven't been identified yet.
Early history Cigars, cigarettes Cancer by the carton Legal history Surgeon General's warning. (CNN) -- Tobacco was first used by the peoples of the pre-Columbian Americas. Native Americans apparently cultivated the plant and smoked it in pipes for medicinal and ceremonial purposes.
1 c.1 BCE: Experts believe American inhabitants have begun finding ways to use tobacco, including smoking (in a number of variations), chewing and in probably hallucinogenic enemas (by the Peruvian Aguaruna aboriginals). 2  c. 1 CE: Tobacco was nearly everywhere in the Americas.