Open

Coming up

Don't miss

Replay


LATEST SHOWS

FASHION

Fashion, what's happened in 2014

Read more

FRANCE IN FOCUS

France: 2014 in review

Read more

#THE 51%

South Africa: Taking a stand against child marriage

Read more

DEBATE

The Future of the Book

Read more

DEBATE

The Future of the Book (part 2)

Read more

REPORTERS

France 24’s best documentaries of 2014

Read more

THE INTERVIEW

'We have to build a new Tunisia', says the president of the Tunisian Parliament

Read more

FACE-OFF

France on alert after attacks: a case of collective hysteria?

Read more

THE INTERVIEW

'Beijing needs to revaluate its policy in the Tibetan areas', says FM of the Tibetan government-in-exile

Read more

Passive smoking may boost the risk of dementia

Latest update : 2009-02-13

According to a study to be published in the British Medical Journal, people constantly exposed to tobacco smoke can be affected by dementia and other cognitive problems. Earlier research has shown an increased risk of heart and lung diseases.

AFP - Exposure to second-hand smoke boosts the risk of dementia and other cognitive problems, even among people who have never smoked, the largest study of its kind reported Friday.

Ill effects on non-smokers of constant exposure to tobacco smoke include an increased risk of lung cancer, diabetes, cardiovascular disease, stroke and death, earlier research has shown.

As for the impact on brain function, active smoking has been found to impair the mind but the evidence for passive smoking has until now been sketchy.

Using new methods in the largest clinical trial to date, a team led by Cambridge University professor David Llewellyn found that even people who had never smoked but kept constant company with smokers performed less well in cognitive tests.

The investigation focussed on nearly 5,000 adults over the age of 50 who were former smokers or who had never smoked.

The volunteers were divided into four groups according to their exposure to passive smoking.

This was determined by saliva samples, which were tested for a by-product of nicotine called cotinine.

Cotinine lingers in the saliva for about 25 days. The higher the levels of cotinine, the higher the exposure to recent second-hand smoke.

The volunteers then took neuro-psychological tests that assessed brain function and cognitive abilities, focusing on memory and the ability to work with numbers and words.

Using the lowest cotinine group as a benchmark, the researchers found a clear and progressively stronger link between impairment in brain function and exposure to second-hand smoke.

In the most-exposed group, the risk of cognitive impairment was 44 percent higher than the benchmark group.

Factors such as age and medical condition, including a history of heart disease, that could have skewed the outcome were all taken into account.

"A similar pattern of associations was observed for never smokers and former smokers," said the study, published in the British Medical Journal (BMJ).

"Given the ongoing international policy debate on exposure to second-hand smoke, this is a topic of major public health significance."

Governments in North America, Australia and Europe have progressively enacted "smoke-free" legislation for the workplaces, bars, restaurants and other public places over the last 15 years.
 

Date created : 2009-02-13

COMMENT(S)