October 29, 2010
Risks: Smokers Found More Prone to Dementia
By RONI CARYN RABIN

Middle-aged smokers are far more likely than nonsmokers to develop dementia later in life, and heavy smokers — those who go through more than two packs a day — are at more than double the risk, a new study reports.

Researchers analyzed the data of 23,123 health plan members who participated in a voluntary exam and health behavior survey from 1978 to 1985, when they were 50 to 60 years old.

Twenty-three years later, about one-quarter of the group, or 5,367, had dementia, including 1,136 with Alzheimer’s disease and 416 with vascular dementia.

After adjusting for other factors, the researchers concluded that pack-a-day smokers were 37 percent more likely than nonsmokers to develop dementia, and the risks went up sharply with increased smoking; 44 percent for one to two packs a day; and twice the risk for more than two packs.

Former smokers and those who smoked less than half a pack a day were no more likely to develop dementia than nonsmokers. The study was published online on Monday in Archives of Internal Medicine.

To its lead author, Dr. Rachel A. Whitmer, an epidemiologist with the Kaiser Permanente Division of Research in Oakland, Calif., the study offered a silver lining: unlike age and family history, she said, “this is one risk factor for dementia that can be changed.”