Roken is ook slecht voor de hersenen.
Uit een Engels onderzoek blijkt dat bij rokers, 50 jaar later,
de cognitieve functies duidelijk verminderd zijn.
Given
the wealth of evidence that smoking damages your health, you would have to be
stupid not to kick the habit. Now a study suggests this could be a
self-fulfilling prophecy, because smoking reduces your IQ.
Lawrence Whalley at the
University of Aberdeen and colleagues at the University of Edinburgh, both in
the UK, looked at how the cognitive ability of 465 individuals, approximately
half of whom were smokers, changed over their lifetime and whether this related
to their smoking habits.
They had all been tested in
1947 at age 11 as part of the Scottish Mental Survey, which made no distinction
between smoking habits. They were tested a second time between 2000 and 2002,
when they were 64 years old.
Smokers performed
significantly worse in five different cognitive tests than did both former
smokers and those who had never smoked. When social and health factors such as
education, occupation and alcohol consumption were taken into account, smoking
still appeared to contribute to a drop in cognitive function.
A link between impaired lung
function and cognitive ageing has long been suspected, though the mechanism is
unclear. One possibility is that smoking subjects the vital organs, including
the brain, to oxidative stress, Whalley says. “Ageing neurons are very
sensitive to oxidative damage.”
Journal reference: Addictive
Behaviors (vol 30, p 77) (dec. 2004)