Second-hand smoke may cause dementia

Cambridge, February 13: A new study has found a link between non-smokers who inhale second-hand smoke involuntarily though, and the risk of dementia in them.

This is not the first study to pin point the existence of an association between passive smoking and an elevated risk of developing dementia. Earlier studies have also established similar links.

But this study is first to specifically establish that “adults” who inhale cigarette smoke of others can suffer from neurological conditions.

Adults who suffer from any kind of heart disease are more likely to develop cognitive problems easily, researchers said. Heart disease is one of the known symptoms that can lead to dementia sooner or later in life and smoking even passively shoots up this risk.

In the study, salivadefine of nearly 5,000 non-smokers aged 50 and above, was tested to check the presence of cotinine, a chemical released as nicotine’s by-product. This chemical has the tendency to stay in the body even two days after inhaling the smoke of others.

Participants of the study were made to go through a series of tests that were designed to check their recall abilities and other skills.

Researchers found in the study that participants with high levels of cotinine in their saliva were 44 percent more likely to develop cognitive disorders compared to those with low levels of the chemical.

"Our results suggest that inhaling other people's smoke may damage the brain, impair cognitive functions such as memory, and make dementia more likely. Given that passive smoking is also linked to other serious health problems such as heart disease and stroke, smokers should avoid lighting up near non-smokers,” lead researcher Dr David Llewellyn, from the University of Cambridge, remarked.

The study findings suggest that it is very important to ban smoking at public places, added Llewellyn.

The findings of the study were published in the British Medical Journal.