Passive smoking could be linked to dementia and other mental diseases, a new study involving Westcountry, U.K., researchers has found.
Researchers from the Peninsula Medical School, the University of Cambridge and the University of Michigan have published the results of the first large-scale study suggesting secondhand smoke exposure could lead to dementia and other neurological problems.
Research has already identified possible links between active smoking and mental deficiencies, and previous findings have suggested exposure to secondhand smoke is linked to poor mental performance in children and adolescents. However, this is the first study of its kind to link secondhand smoke exposure to dementia and other brain diseases in adult non-smokers.
The research team examined saliva samples from almost 5,000 non-smoking adults over the age of 50, using data from the Health Survey of England.
The saliva samples were tested for cotinine, a product of nicotine that remains in the saliva for about 25 hours after exposure to secondhand smoke. Those who took part in the study also provided a detailed smoking history, and those who had never smoked, or who were previous smokers, were assessed separately.
The researchers believe the link between secondhand smoke and cognitive impairment could be explained by the fact that heart disease increases the risk of developing dementia, and that exposure to secondhand smoke is known to cause heart disease.
