Smoking Tied to Memory Loss in Middle Age

By Steven Reinberg
HealthDay Reporter
Tuesday, June 10, 2008; 3:00 AM

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MONDAY, June 9 (HealthDay News) -- Middle-aged smokers are more prone to memory problems than their non-smoking peers, a new French study suggests.

While smoking is a recognized health hazard, there has been some debate on its effect on dementia, the study authors said.

"Dementia is rare among middle-aged people, but cognitive function at this age in closely related to dementia," said lead researcher Severine Sabia, of the Institut National de la Sante et de la Recherche Medicale in Villejuif, France. "Our results show that smoking is associated with poorer cognition and decline over five years.

"Another interesting finding," Sabia added, "was that ex-smokers improved their other health behaviors, and among them there was little residual adverse effect of smoking on cognition."

The findings are published in the June 9 issue of the Archives of Internal Medicine.

For the study, the researchers collected data on 10,308 British civil servants who ranged in age from 35 to 55 and were enrolled in the Whitehall II study. Between 1985 and 1988 and again in 1997 and 1999, they were asked about their smoking habits. Nearly 5,400 people completed tests of memory, reasoning, vocabulary and verbal fluency in 1999. Five years later, 4,659 of the study participants were retested.

During the first round of cognitive testing, people who smoked ranked in the lowest 20 percent of all those examined, compared with people who had never smoked. But, people who were ex-smokers were 30 percent less likely to have poor vocabulary and low verbal frequency scores than current smokers.

"Smoking is associated with poorer cognitive function in midlife," Sabia said. "However, 10 years after smoking cessation, there is little adverse effect of smoking on cognition."

The study also found that ex-smokers had better overall health habits than smokers. They drank less alcohol, exercised more and ate more fruits and vegetables, the researchers found.

"With the ageing population and the projected increases in older adults with dementia, it is important to identify modifiable risk factors," Sabia said. "Our results suggest that smoking had an adverse effect on cognitive function. Thus, public health messages should target smokers at all ages."