Dementia And Smoking

Overview

Dementia is a neurodegenerative disease that mainly occurs over the age of 65. It has been linked to a variety of causes, and a genetic component has been suggested in some types of dementia. However, the main concern of this article is smoking in relation to dementia. Smoking is generally adverse to your health, most notably by increasing the risk of lung cancer.¹ It can also increase the risk of dementia by affecting the blood vessels in the brain.

What is dementia?

Dementia is an umbrella term for neurodegenerative disorders in old age. These disorders affect the brain and cause dysfunction in cognitive functioning. The most notable form of dementia is Alzheimer’s Disease which is currently incurable and is thought to be due to protein plaques and tangles which hamper the communication between neurons. An analogy of this is when hair (the proteins) clogs the shower drain blocking water (information) from travelling in the pipes (neurons). Fortunately, there is progress in therapeutics for Alzheimer’s, with a recent drug slowing mental decline in a clinical trial. This leads to the hope that dementia will be effectively treated in the future.

The other forms of dementia will have different hallmarks. For example, Lewy body dementia is characterised by the formation of Lewy bodies. This is the form of dementia that Robin Williams had.

Symptoms of dementia

Generally, there are shared symptoms between the types of dementia which allow their grouping together under the umbrella term. The main characteristic of all dementias is the cognitive decline that these diseases cause. Cognitive decline occurs normally in old age, but dementia is an advanced form of this. In early-onset Alzheimer’s disease, cognitive decline can occur in people as young as 45. However, there are other common symptoms of dementia which can be separated into early and late forms of symptoms. Early symptoms include:

• Memory loss
• Difficulty concentrating and carrying out daily tasks
• Struggle to follow a conversation
• Confusion e.g., time or place you’re in
• Mood changes

There are also symptoms in the later stages of dementia:

• Memory problems - failing to recognise family/friends
• Communication problems - slowly losing the ability to speak before abandoning speech altogether. Non-verbal cues can help when this is the case
• Behavioural problems - psychological symptoms such as anxiety or depression
• Bladder incontinence
• Appetite and weight loss problems

Smoking increases the risk of dementia

Smoking has been linked to adverse health effects in many ways, but one way is increasing the risk of dementia. A study investigated this link and found that smoking, and the amount of smoking, significantly increased the risk of dementia.² More recent studies have upheld this link and also found that ceasing to smoke decreases the risk of dementia.³ It has been posed that this increased risk is due to the inflammation caused by chemicals in cigarettes which damage the vascular system in the brain. 

Smoking causes the cerebral cortex to thin

A study published in Nature in 2015 found that smoking can actually cause a reduction in the thickness of the cerebral cortex.⁴ This robust study established the structural changes that can occur from smoking which might underlie cognitive decline in dementia. Where previous studies had only established a link, this provided direct evidence of the negative effect smoking can have on the brain. In addition, this study also found that cortical thinning can be reversed with smoking cessation. Thus providing further reasons to quit smoking. 

Chemicals in cigarettes promote neuronal degeneration

While the Nature paper above found that the cerebral cortex thinned with smoking, the mechanism of how this occurs is not mentioned in the paper. It is likely to occur as chemicals in cigarettes are thought to promote neuronal degeneration. The cerebral cortex is basically made of neurons.  A subsequent study in 2016 found that smoking impacted neuronal degeneration, making it a risk factor for dementia.⁵  This was opposed to causing vascular damage to contribute to dementia, which smoking also causes.

Tips on quitting smoking

As outlined above, smoking can have real detriments to your health. It follows that you should quit smoking to prevent further damage and also to recover some of the damage that has already been done. However, this is quite difficult as nicotine is a highly addictive substance. Below is a list of tips that could help you quit smoking:

• List the reasons why you’re quitting and tell friends/family
• If you tried to quit before, remember what worked
• Use stop-smoking aids such as nicotine patches
• List your smoking triggers and try to avoid them
• Keep cravings at bay by being busy and trying to exercise more
• Don’t be afraid to seek support and advice

Summary

Smoking is a habit that can produce adverse health effects due to the chemicals that are contained in the smoke. This article has investigated the link between smoking and dementia by providing evidence that smoking is a risk factor. This is likely to occur due to damage to the vascular system in the brain and by promoting neuronal degeneration leading to cortical thinning. Due to these health effects, attempts at quitting smoking should be made. Studies also found that quitting smoking can reverse the adverse health effects.