The impairment of memory in middle aged adults shown to be directly linked to their smoking habit.
The study reveals a direct relationship between smoking and memory loss. When studied, long term smokers showed a reduction in cognitive function in mid life. When smoking was ceased for 10 years, these results disappeared.
Even more interesting was the fact that ex-smokers showed a lower risk of memory, vocabulary and verbal fluency impairment than did non-smokers. Researchers believe this result may be linked to the others improved behaviors followed once a long term smoker quits the habit
These findings are rooted in data from the more than 10,000 people who previously participated in the Whitehall II study. The Whitehall II focused on male and female civil workers between the ages of 35 and 55. Smoking history was taken and then reevaluated approximately 10 years later. By 1999, total cognitive test information was available for more than 5000 original participants.
In the study, those who never smoked were more likely to follow up with cognitive testing. The smokers, however, were at increased risk of dying during the follow-up and not participating in cognitive testing.
By 1999, the smoking participants were nearly 40% more likely to suffer from impairment of cognition than the participants who never smoked. The ex-smoker, however, was 30% less likely to suffer from verbal impairments, including poor vocabulary and verbal fluency, than those who chose to never smoke.
While the results of the study were positive, the researchers note that the inconsistency of data lends them to the need for replication. A new Whitehall study is being formulated with better cognitive tests.