JAMA Logo Already known to heighten chances of developing various health risks, here is another article which pens down the adverse effects of smoking. A latest study asserts that heavy smoking in middle age is correlated with more than twice the risk of Alzheimer’s disease and other forms of dementia in later years. It has been estimated that every year more than a million deaths are caused due to smoking.

Prior investigations have suggested that the chances of developing Parkinson’s disease and other neurodegenerative conditions are reduced in smokers. But it now seems that the correlation between smoking and risk of Alzheimer’s disease is controversial. In order to ascertain the exact link between dementia and smoking, authors scrutinized data from 21,123 members of one health care system who participated in a survey between 1978 and 1985. The age of all the volunteers ranged from 50 to 60 years during the survey. Experts kept a tab on dementia Alzheimer’s disease and vascular dementia cases from January 1, 1994 through July 31, 2008, in this period participants aged around 71.6 years.

Investigators quote, “It is possible that smoking affects the development of dementia via vascular and neurodegenerative pathways. To our knowledge, this is the first study evaluating the amount of midlife smoking on long-term risk of dementia and dementia subtypes in a large multiethnic cohort. Our study suggests that heavy smoking in middle age increases the risk of both Alzheimer’s disease and vascular dementia for men and women across different race groups. The large detrimental impact that smoking already has on public health has the potential to become even greater as the population worldwide ages and dementia prevalence increases.”

Minna Rusanen, M.D., of University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland, and colleagues discovered 5,367 participants forming 25.4 percent with dementia during an average of 23 years of follow-up. Among the total patients while 1,136 reported Alzheimer’s disease, 416 had vascular dementia. Individuals smoking more than two packs a day in middle age were probably at an increased risk of dementia overall and also of each subtype, Alzheimer’s disease and vascular dementia, than non-smokers. Those who were former smokers or smoked less than half a pack per day apparently revealed no elevated threats. The link between smoking and dementia probably did not differ by race or sex.

The study will be published in the February 28 print issue of Archives of Internal Medicine, one of the JAMA/Archives journals.