My mother died recently after suffering from Alzheimer's for 20 + years. It was a terrible experience for her and a helpless time in my family's life. There wasn't anything we could do. Her memory just faded to black like an old "B movie". She eventually forgot how to swallow and spent the last 3 weeks of her life in what we suppose was a physically painful hospice.
So when I read this new study out of Neuroimage (2011 Jan 31) called "24-Month effect of smoking cessation on cognitive function and brain structure in later life" I was immediately enthralled. One of the tools used to quantify cognitive function was the Alzheimer's Disease Assessment Scale cognitive subscale or ADAS-cog for short. I blogged earlier about an article which explained how parts of a smoker's brain shrinks over time. Surprisingly, it's one of my most popular posts.
This study by Almeida and others, looked to determine if smoking cessation decreased the progression of cognitive decline later in life. They enrolled lots of people and had all the usual scientific parameters that they followed. They found that unsuccessful quitters (UQ) had worse cognitive scores than never smokers (NS) and successful quitters (SQ) over a 24 month research term. The SQ cohort was defined as having quit for a minimum of 547 days during the follow up period.
They also observed worsening immediate and delayed recall in the UQ group compared to the NS group. They adjusted the results for age, baseline cognitive performance, alcohol use, years of education, depression scores and the presence of chronic respiratory disease.
They went on to perform an imaging scan of the participants' brains. The UQ enrollees had a disproportional loss of gray matter in their right thalamus, semi-lunar lobule and parietal lobe over the 24 month period compared to the NS counterparts. This is similar to what was found in the previous study I mentioned.
The successful quitters also showed a loss of gray matter compared to the never smoker group but in different regions: the right middle and inferior occipital gyri, left superior frontal gyrus and the right and left culmen. The UQ did not lose any more gray matter than the SQ over the 24 month follow up period. This study's findings are very consistent with what we already know - smoking causes a cognitive decline and loss of gray matter over time.
So what is the take home message? First of all, if you aren't a smoker, then great. Don't even think about starting. Second, if you are a smoker, then stop as early as you can. The sooner the better. There are too many quit smoking benefits to continue the habit. Get help and get it now. We have lots of resources here to help. The more you learn, the more you'll want to stop.
