Long-term smoking 'may cause' brain shrinkage

Conclusion This study has shown an association between smoking and a thinner cortex, though it cannot prove that smoking caused the cortex to thin. The study was cross sectional, so cannot say which came first – the smoking or the cortex differences. Also, confounding factors other than smoking may be contributing. Strengths of the study include: Having access to measurements of cognitive ability when the participants were 11 years old, before most of them would have started smoking, as a potential indicator of cortex thickness. The radiologists were blinded to which MRIs came from each group, reducing the risk of them introducing bias based on interpreting scans differently for people they knew to be smokers. All participants were the same age when they had the MRI scan, so age did not need to be adjusted for in the results. This is important because the cortical thickness naturally decreases with age. The fact that those who gave up smoking seemed to have less difference to the non-smokers than those who continued to smoke fits with the idea that the two factors might be related to each other rather than arising just by chance. Limitations acknowledged by the authors include: The number of current smokers was small, only 36. It is possible there were differences in cortex thickness before a person started smoking. They say that structural changes in the frontal part of the brain related to impulse control may have made it more likely for pe...
Source: NHS News Feed - Category: Consumer Health News Tags: Lifestyle/exercise Neurology Source Type: news