Exposure to Secondhand Smoke May Raise Dementia Risk

February 25, 2009 — Smoking is an established risk factor for cognitive impairment and dementia, and now a new large study suggests secondhand smoke is also detrimental.

"The odds of cognitive impairment were 44% higher in those exposed to the highest levels of secondhand smoke compared with those exposed to negligible levels," lead author David Llewellyn, PhD, from the Department of Public Health and Primary Care at the University of Cambridge, in the United Kingdom, told Medscape Neurology & Neurosurgery.

Results from the national population-based study are published online February 12 in BMJ.

Investigators examined saliva samples from almost 5000 nonsmoking adults older than 50 years. Participants were part of the Health Survey for England and had also taken part in the English Longitudinal Study of Aging. Saliva samples were tested for cotinine — a product of nicotine that can be found for about 25 hours after exposure to secondhand smoke. Participants in the study also provided a detailed smoking history. Investigators assessed never smokers and previous smokers separately.

High Levels of Cotinine Linked to Cognitive Impairment

READ :  http://www.medscape.com/viewarticle/588691?src=nldne