(February 13, 2009 - Insidermedicine) Second-hand smoke exposure may increase the risk of developing cognitive impairment among older adults, according to research published in the British Medical Journal.

Here is some information about second-hand smoke:

•    Adults regularly exposed to second-hand smoke are at increased risk for lung cancer and heart disease.

•    Children are at increased risk for asthma and ear infections.

•    Babies are at increased risk of sudden infant death syndrome (SIDS)

Researchers from the University of Cambridge obtained saliva samples and full smoking history from nearly 5,000 non-smokers aged 50 or older. They tested the saliva for cotinine, a biomarker for nicotine. The participants were also assessed for their level of cognitive functioning.

Those with the highest cotinine concentrations in their saliva were nearly 50% more likely to suffer from cognitive impairment than those with the lowest concentrations. Similar patterns were seen among participants who had never smoked as for those who were former smokers.

Today's research links cognitive impairment in adulthood with second-hand smoke and provides another reason to limit public smoking.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.