Pubdate: Fri, 19 Jun 1998
Source: San Jose Mercury News (CA)
Contact:  http://www.sjmercury.com/

SMOKERS MORE LIKELY TO DEVELOP DEMENTIA, STUDY SAYS

Research: Largest project of its kind shows `powerful' link to tobacco.

LONDON (AP) -- Smokers are twice as likely as lifetime non-smokers to
develop Alzheimer's disease and other forms of dementia, a study published
today suggests.

Results of other studies differ on whether smoking increases the risk of
developing Alzheimer's or somehow protects against it, but scientists say
the latest study by researchers at Erasmus University in the Netherlands is
important because it is the largest to investigate the link -- and the first
major project to have evaluated people before they developed brain disease.

Dr. Anthony Mann, an old-age psychiatrist and professor of epidemiology at
the Institute of Psychiatry in London, called the findings ``powerful.''

``They are the first to do a prospective study, and it's the largest to show
a positive link,'' said Mann, who wasn't involved in the research. ``It's
the best we've had.''

The study in Britain's Lancet medical journal followed 6,870 men and women
ages 55 and older living in a suburb of Rotterdam. It found that smokers
were 2.2 times as likely to develop dementia of any kind and had a risk for
Alzheimer's disease that was 2.3 times as high as those who had never smoked
cigarettes.

Alzheimer's disease is the most common form of dementia, estimated to
afflict nearly 18 million people worldwide, or 3 percent of people over the
age of 60, according to the non-profit Alzheimer's Disease International.

Unlike previous studies, none of the people in the Rotterdam study had
dementia when first examined. They were asked about their smoking habits and
divided into smokers, former smokers and those who had never smoked. Two
years later, 146 study participants had developed dementia and 105 of those
had been diagnosed with Alzheimer's disease.

Within a random sample of the whole group, the researchers also examined the
effect of smoking on people who carried a gene believed to increase the risk
of Alzheimer's disease. They found that despite the overall finding that
smoking doubled the risk of developing the degenerative disease, smokers who
carried the gene actually were no more likely to develop Alzheimer's than
non-smokers.

But smokers who did not carry the gene were found to be four times as likely
to develop the disease as non-smokers, the study said.

Scientists are unsure exactly how smoking might contribute to Alzheimer's.

Still, Mann said, ``It takes forward that things that put you at risk for
vascular disease put you at risk for dementia in general.''

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Checked-by: "Rolf Ernst"