Passive smoking could increase the risk of developing dementia and other forms of cognitive impairment, according to a new research.
The research, by Dr David Llewellyn from the University of Cambridge and his collaborators which is published in the British Medical Journal, highlighted a 44 per cent increase in risk of cognitive impairment for those who are exposed to high levels of passive smoking or second hand smoke.
Previous studies identified active smoking as a risk factor for cognitive impairment and dementia. However, this is the first large scale study to conclude that passive smoking could lead to dementia and other neurological problems in adults.
The previous findings suggested that second hand smoke exposure could impair cognitive development in children and adolescents.
The research, led by Dr Llewellyn, used saliva samples from nearly 5,000 non smoking adults over the age of 50. By measuring levels of cotinine (a by-product of nicotine) in their saliva and taking a detailed smoking history, the researchers were able to assess levels of exposure to second hand smoke.