Heavy smoking in midlife may be associated with dementia in later years

Oct 25, 2010

Heavy smoking in middle age appears to be associated with more than double the risk for Alzheimer's disease and other forms of dementia two decades later, according to a report posted online today that will be published in the February 28 print issue of Archives of Internal Medicine.

Current estimates suggest smoking is responsible for several million deaths per year from causes such as and cancer, according to background information in the article. Although smoking increases risks of most diseases and of death, some studies have shown a reduced risk of Parkinson's disease and other neurodegenerative conditions among smokers. "The link between smoking and risk of Alzheimer's disease, the most common subtype of , has been somewhat controversial, with some studies suggesting that smoking reduces the risk of ," the authors write.

Minna Rusanen, M.D., of University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland, and colleagues analyzed data from 21,123 members of one who participated in a survey between 1978 and 1985, when they were 50 to 60 years old. Diagnoses of dementia, Alzheimer's disease and vascular dementia were tracked from Jan. 1, 1994 (when participants were an average of 71.6 years old), through July 31, 2008.

A total of 5,367 participants (25.4 percent) were diagnosed with dementia during an average of 23 years of follow-up, including 1,136 with Alzheimer's disease and 416 with vascular dementia. Those who smoked more than two packs per day in middle age had an elevated risk of dementia overall and also of each subtype, Alzheimer's disease and vascular dementia, compared with non-smokers. Former , or those who smoked less than half a pack per day, did not appear to be at increased risk.

Associations between smoking and dementia did not vary by race or sex. Smoking is a well-established risk factor for stroke, and may contribute to the risk of vascular dementia through similar mechanisms, the authors note. In addition, smoking contributes to oxidative stress and inflammation, believed to be important in the development of Alzheimer's disease. "It is possible that smoking affects the development of dementia via vascular and neurodegenerative pathways," the authors write.

"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," they conclude. "Our study suggests that heavy smoking in middle age increases the risk of both Alzheimer's disease and 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."

Explore further: Financial incentives help economically-disadvantaged pregnant smokers quit and improve fetal growth

More information: Arch Intern Med. 2010. Published online October 25, 2010. doi:10.1001/archinternmed.2010.393

add to favorites email to friend print save as pdf

Related Stories

Smokers are more likely to develop dementia

Sep 04, 2007

People who smoke are more likely to develop Alzheimer’s disease or dementia than nonsmokers or those who smoked in the past, according to a study published in the September 4, 2007, issue of Neurology.

Low childhood IQ linked to type of dementia

Jun 26, 2008

Children with lower IQs are more likely decades later to develop vascular dementia than children with high IQs, according to research published in the June 25, 2008, online issue of Neurology®, the medical journal of the ...

Having a parent with dementia may affect memory in midlife

Feb 18, 2009

People who have parents diagnosed with Alzheimer's disease or dementia may be more likely to have memory loss themselves in middle age, according to a study released today that will be presented at the American Academy of ...

Statins may protect against memory loss

Jul 28, 2008

People at high risk for dementia who took cholesterol-lowering statins are half as likely to develop dementia as those who do not take statins, a new study shows.

Recommended for you

AMA examines economic impact of physicians

18 hours ago

(HealthDay)—Physicians who mainly engage in patient care contribute a total of $1.6 trillion in economic output, according to the American Medical Association (AMA)'s Economic Impact Study.

Less-schooled whites lose longevity, study finds

18 hours ago

Barbara Gentry slowly shifts her heavy frame out of a chair and uses a walker to move the dozen feet to a chair not far from the pool table at the Buford Senior Center. Her hair is white and a cough sometimes interrupts her ...

How to keep your fitness goals on track

18 hours ago

(HealthDay)—The New Year's resolutions many made to get fit have stalled by now. And one expert thinks that's because many people set their goals too high.

User comments : 0

More news stories

Teachers' scare tactics may lead to lower exam scores

As the school year winds down and final exams loom, teachers may want to avoid reminding students of the bad consequences of failing a test because doing so could lead to lower scores, according to new research published ...