According to a new study, people, who have significant exposure to passive smoke, have 44% higher risk of becoming a victim of 
dementia.
Though some previous studies have found some links between higher risk of Alzheimer’s and dementia, the current study is the leading review till today which shows a relation between dementia risk and secondhand smoke.
“There is a link between secondhand smoke exposure and cognitive function that is often, but not always, reckoned a sign of dementia,” says Iain Lang, the lead author of the study.
According to Lang, the amount of passive smoke exposure serves as the risk factor for impaired cognitive function and those people, who have higher exposure, are at considerably higher risk of the disease.
The study has been published in the journal BJM online issue.
For their study, the researchers received data on nearly 4800 non-smokers aged 50 and above. To know about the levels of cotinine, the researchers examined the saliva samples of these people. Cotinine is a nicotine product and it remains in saliva even after 25hr of smoke exposure. The participants of the study also had to undergo neuropsychological tests to know about their cognitive impairment and brain function.
The researchers noticed that those who had highest cotinie levels in their salvia were at 44% higher risk for cognitive impairment when compared to the people who had lowest levels of cotinine.
