Exposure to second-hand smoke 'ups dementia risk'

London, Feb 13 (ANI): A new study has revealed that exposure to second-hand smoke could increase the risk of developing dementia and other neurological problems.

For the study, Dr David Llewellyn and his research team from the University of Cambridge, Peninsula Medical School and the University of Michigan, examined saliva samples from almost 5000 non-smoking adults over the age of 50 using data from the 1998, 1999 and 2001 waves of the Health Survey for England (HSE).

The samples were tested for cotinine - a product of nicotine that can be found in saliva for about 25 hours after exposure to second-hand smoke.

Participants in the study also provided a detailed smoking history. Never smokers and previous smokers were assessed separately.

The researchers used established neuropsychological tests to assess brain function and cognitive impairment.

These focused on memory function, numeracy and verbal fluency - for example naming as many animals in a minute. The results of the tests were added together to provide a global cognitive function score.

Participants whose scores were in the lowest 10 percent were defined as suffering from some level of cognitive impairment.

The authors argue that the link between second-hand smoke and cognitive impairment could be explained given that heart disease increases the risk of developing dementia and second-hand smoke exposure is known to cause heart disease.

The study is published on bmj.com. (ANI)