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Smoking and IQ

November 14, 2005

It is well known that smoking cigarettes is bad for your lungs and your heart. Now new research suggests it may also be bad for your brain.


Does smoking choke the brain? I’m Bob Hirshon and this is Science Update.

Smokers often light up when they need to focus and think. But in the long run, smoking cigarettes may actually drag down your IQ. That’s according to research psychiatrist Jennifer Glass of the University of Michigan. In a recent study, she and her colleagues found that the longer and more heavily someone smoked, the lower their scores on an IQ test. This was regardless of age, education, or other substance abuse.

Although other recent studies have had similar findings, Dr. Glass says it’s not yet clear how or even if smoking actually causes a mental decline.

JENNIFER GLASS (University of Michigan):
But we do hypothesize or speculate that as smoking is damaging the blood vessels, that it may be impairing blood flow and oxygen in the brain.

If so, it would be important to find out if quitting smoking could bring the mind back to full capacity. I’m Bob Hirshon, for AAAS, the science society.