Heavy smoking in midlife is associated with greater than 100% increase in risk of dementia 2 decades later.

Analysis of prospective data from a multiethnic group of over 21,000 members of a health care system has found over a follow-up period of 23 years that the risk for dementia increased as the amount of smoking increased (fully-adjusted data). Specifically, those who smoked more than two packs a day in midlife had more than 2 times the risk (2.14) compared to those who did not smoke.

PositiveTip: The single best thing a smoker can do to improve their health--in the short- and long-term--is to quit!