Smoking has been associated with increased risk of vascular disease, including vascular dementia and stroke. Smokers have poorer blood supply to the brain and have an increased risk of damage to the brain as a result of interrupted blood flow (cerebral infarct). The magnitude of damage seems to be in accordance with number of cigarettes smoked.
Smoking and loss of brain volume
Research that compared the grey matter volumes in the brains of smokers and non-smokers found that smokers had less grey matter volumes than non-smokers in certain parts of the brain. The biggest difference was seen on the sides of the frontal cortex, the part of the cortex that seems especially vulnerable to age-related decline, so apparently smoking does not only make your skin age prematurely, but your brain also.
The smoking mind – impact on cognitive skills
Studies on middle-age and older individuals, show that the cognitive abilities of non-smokers are better than smokers and that current smokers have increased risk of cognitive decline compared with non-smokers (whether they are former smokers or have never smoked). Some (certainly not me) might assert that the smarter people do not take up smoking, so that this difference in cognitive skills might have been there all along and has nothing to do with smoking. This point is difficult to refute as most of the research does not have any measures of cognitive abilities of smokers before they became smokers. There is an exception though. One study measured cognitive skills of 470 individuals, first when they were 11 years old and a second time when they were 80 years old. Results showed that those who smoked at the age of 80 showed poorer performance than those who had stopped smoking and those who had never smoked, even after taking their performance at 11 years old into account.
Here is a video from youtube, explaining why people get addicted to nicotine:
-Anstey, K. J., von Sanden, C., Salim, A. og O’Kearney, R. (2007). Smoking as a risk factor for dementia and cognitive decline: A meta-analysis of prospective studies. American Journal of Epidemiology, 166(4), 367-378.
-Brody, A. L., Mandelkern, M. A., Jarvik, M. E., Lee, G. S., Smith, E. C., Huang, J. C. o.fl. (2004). Differences between smokers and nonsmokers in regional gray matter volumes and densities. Biological Psychiatry, 55(1), 77-84.
-Raz, N., Gunning-Dixon, F., Head, D., Rodrigue, K. M., Williamson, A. og Acker, J. D. (2004). Aging, sexual dimorphism, and hemispheric asymmetry of the cerebral cortex: replicability of regional differences in volume. Neurobiology of Aging, 25(3), 377-396.
-Swan, G. og Lessov-Schlaggar, C. (2007). The Effects of tobacco smoke and nicotine on cognition and the brain. Neuropsychology Review, 17(3), 259-273.