Tobacco stunts your grey matter, claim scientists

SCIENTISTS have found that heavy smokers have less grey matter in their brains, which could make them more impulsive than non-smokers.

The recent study, which examined the brains of 35 volunteers, found that not only were there fewer thinking cells in smokers’ brains, but they also had a lower density.

It also found a connection between the amount smoked, and the size and density of areas in the brain which are linked to higher nicotine dependance and increased impulsivity.

Scans revealed abnormalities in the prefrontal cortex - an area at the front of the brain involved in "executive functions" such as decision-making, planning and judgment. It is also linked to poorer memory performance.

While the health consequences of smoking are well known, it is the first time that brain mapping has been used to document the volume and density of the grey matter in smokers’ brains. Grey matter, so named because it looks grey to the naked eye, consists largely of the cell bodies of neurons, the heads of nerve cells.

Researchers at the Neuropsychiatric Institute at the University of California, who studied 19 otherwise healthy smokers and 17 non-smokers, said:

"These findings may reflect effects of chronic smoking, predisposing traits that lead to smoking, or some combination of these factors."

But Dr Klaus Ebmeier, Professor of Psychiatry at the University of Edinburgh, said firm conclusions were difficult to draw from the study. He said: "It could be that smokers have a smaller brain, or it could mean that smoking damages the grey matter in the brain. It could also mean that smoking had other effects which caused the reduction of grey matter."