Smoking, drinking, and incident cognitive impairment: a cohort community based study included in the Gospel Oak project

Objectives-Recent longitudinal studies have reported that smoking increases risk for cognitive impairment and that moderate alcohol intake could be pr eventive. The association between both cigarette smoking and alcohol drinki ng and incident cognitive impairment was studied in a representative popula tion. Methods-This is a 1 year prospective population based cohort sudy of all re sidents aged 65 or over in the electoral ward of Gospel Oak in London, UK ( n=889). Cognitive impairment was assessed at baseline and 1 year later usin g the organic brain syndrome (OBS) cognitive impairment scale from the shor t CARE structured assessment. Subjects who were cognitively impaired at bas eline were excluded from this analysis. Results-The prevalence of OBS cognitive impairment was 10.4% at index asses sment and the 1 year cumulative incidence of cognitive impairment was 5.7%. Cognitive impairment was not associated with use of alcohol, although ther e was a non-significant association in the direction of a protective effect against onset of cognitive impairment for moderate drinkers compared with non-drinkers and heavy drinkers. Current smoking status predicted cognitive impairment (risk ratio (RR) 3.7; (95% confidence interval (95% CI)=1.1-12. 3) independently from sex, age, alcohol, occupational class, education, han dicap, depression, and baseline cognitive function. Conclusions-Smoking seems to be a prospective risk factor for incident cogn itive impairment; thus encouragement of older people to stop smoking could be considered as part of a strategy to reduce the incidence of cognitive im pairment.