A study published in the June 2007 edition of the American Journal of Epidemiology has revealed that older smokers are at an increased of developing dementia and of cognitive decline, compared with non-smokers.

According to the research, undertaken by Australian National University Centre for Mental Health Research, current older-aged smokers are at an up to 80% higher risk of Alzheimer’s disease and vascular dementia than their non-smoking peers.

“Overall, the results of this study clearly show that, when compared with people who have never smoked, current smokers have an increased risk of dementia and cognitive decline ranging from 40 percent to 80 percent, depending on the type of dementia or cognitive outcome examined” said research leader Associate Professor Kaarin Anstey.

Researchers analysed 19 high quality longitudinal studies on smoking among older adults, with a mean age of 74. The study included a total of 26,374 participants followed for dementia for up to 2 - 30 years, and 17,023 participants followed for up to 2 - 7 years to assess cognitive decline. The study looked at current smokers, ever smokers, former smokers and non-smokers.

“Based on this research, public health information should be updated for smokers to include a warning that smoking may increase the risk of dementia,” Associate Professor Anstey said.

Further research is also needed to determine the period of time after which the risk begins to decline.