The link between smoking and dementia: Dr Ross Walker investigates

Although I would like to blame smoking for all of the world’s medical ills, there are some conditions where there is no particular link. But, come the revolution, and I’m running the show, cigarette smoking would be wiped off the face of the earth.

There is no doubt that cigarette smoking and obesity are the two major preventable causes of many common illnesses. There is a direct link between cigarette smoking and the following illnesses:

• Cardiovascular disease: 60 per cent of smokers will develop some form of cardiovascular disease e.g. Heart attack, stroke or peripheral vascular disease (arterial blockages in the legs)
• Chronic airways disease: 60 per cent of smokers will develop either emphysema or chronic bronchitis as a consequence of long-term smoking. It is a sad fact that close to 100 per cent of asthmatics to smoke will develop severe chronic lung disease.
• Lung cancer: 20 per cent of smokers will develop lung cancer. Interestingly, it is also a little-known fact that 20 per cent of lung cancer has nothing to do with smoking.
• Bladder cancer: There is a strong link between smoking and this relatively common form of cancer.
• Upper airway and upper gastrointestinal cancers such as throat and oesophageal cancers are also linked to cigarette smoking.

But, a recent study published in the Journal of Alzheimer’s Disease analysed the link between cigarette smoking and dementia. It has been estimated that 50 million people worldwide suffer some form of dementia of which 60-70 per cent is the common form, Alzheimer’s disease. The Alzheimer’s Disease Centre in Kentucky followed 531 older people for on average 11-and-a-half years who had no evidence of cognitive impairment (i.e. early Alzheimer’s) at the start of the study. Forty-nine were current smokers and 231 were former smokers. Of the 531 people in the study, 111 were diagnosed with dementia whilst 242 died without dementia.

Cigarette smoking was associated with early death but not with dementia. I believe there is a clear explanation for this. When you smoke one cigarette, you are taking 48 well-documented poisons into your body. The least poisonous of these 48 chemicals is the highly addictive nicotine, which is what hooks you on smoking in the first place. But, it appears that it is the other 47 poisons that creates the myriad of diseases I have listed above.

One in five people carry the receptors in their brain for nicotine addiction and this is why 50 years ago half the population smoked, but when they found out about the dangers of cigarettes, many people quit. However, there was still that ingrained 20 per cent of people who continued smoking. Fortunately, in Australia smoking numbers are now down to around 13 per cent of the adult population. Of course, I would prefer this to be zero.

But it does appear that stimulating the nicotine receptors in the brain has some degree of protection against Alzheimer’s disease and Parkinson’s disease. This, of course, does not justify anyone smoking, but certainly opens the possibility for using specific nicotine-related therapy or a less addictive similar chemical as a potential therapy for these conditions once it has been established that this is the case.

Regardless, if you’re a smoker, you should never see any justification for your habit. Every time you puff on one of those disgusting white sticks you are running the risk of all manner of lethal diseases and certainly giving yourself a chance of not making it to the age where you may have a weak protection against Alzheimer’s disease.

Do you smoke, or did you ever smoke? What are your thoughts on this?