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.
Two major types of tobacco constituted the bulk of the crop grown in Virginia from about 1650 to the 1730s: sweet-scented and Orinoco. The milder, sweet-scented tobacco was unique to Virginia and traces back to about 1650, when Edward Digges planted seeds of the Orinoco variety of tobacco on Digges Neck, a tract of land he had acquired on the York River.