Recently, there has been a lot of controversial information about smoking and dementia. Does it damage brain health?
Some studies strongly state that smoking increases dementia risk.
Other research reveals that there is no link between dementia and smoking. Some reports even suggest that active smoking has beneficial effects on the brain.
Conversely, there is evidence suggesting that active smoking has neurotoxic effects that double the risk of dementia for older adults.
Is There a Link Between Smoking and Dementia?
Tobacco is already recognized as one of the risk factors for several non-communicable diseases. These include diabetes, cancers, chronic lung disease, and cardiovascular diseases.
According to Dr. Douglas Bettcher, tobacco is one of the largest threats to public health killing almost six million people every year.
Below, we will look at both sides of the debate.
This will give a better understanding of whether smoking increasing a person’s risk of getting dementia or not.
Studies Supporting the Fact that Smoking Increases Risk of Dementia
WHO (World Health Organization) published information stating that smokers have a 45% higher risk of developing dementia when compared to non-smokers.
This was done in collaboration with ADI (Alzheimer’s Disease International).
WHO reviewed the evidence that showcases a strong relationship between smoking and dementia risk. The organization also concluded that the risk becomes higher the more an individual smokes.
This is one of the reasons the organization is at the forefront of encouraging people to quit smoking because of all the negative effects it has.
It is estimated that about 14% of Alzheimer’s cases in the globe are attributed to smoking.
Alzheimer’s Society UK supports this statement explaining that there is strong evidence that smoking can increase a person’s risk of developing dementia.
Although not every smoker will end up with dementia, quitting smoking is thought to reduce the risk of equating it to that of non-smokers.
One of the primary reasons behind this is that vascular dementia and Alzheimer’s disease the two most common dementia forms are linked to issues with the vascular system i.e. blood vessels and heart.
Smoking is known to increase the risk of suffering vascular problems through smaller bleeds inside the brain or strokes.
These are among the top dementia risk factors.
Additionally, the toxins present in cigarette smoke are known to increase inflammation and oxidative stress
Does Second-Hand Smoking Increase the Risk of Dementia?
WHO also warns that passive smoking or exposure to 2nd hand smoke can also increase the risk of developing dementia.
A Cardiovascular Health Cognition Study published in the American Journal of Epidemiology in 2010 supports the statement that second-hand smoke (SHS) can increase the risk of developing dementia.
The researchers observed 5,201 participants from different parts of the US all of who were 65 years or older for one year.
They also followed another group comprising African American participants for 12 months as well.
Out of these groups, the experts recorded 3,608 participants who had developed dementia after follow-ups.
The researchers asked the subjects if they had lived with a regular smoker and the number of years this happened.
They found out that over 60% of the individuals have lived with a smoker for over 15 years.
The experts concluded that exposure to high levels of second-hand smoking, as well as carotid artery stenosis, was associated with a higher risk of developing dementia, especially over six years.
This study also revealed that the risk of dementia increased three times for people who had more than 25 years of exposure to second-hand smoke.
SHS affects your body in the negative, too
The study goes ahead to explain that tobacco smoke contains numerous carcinogenic or toxic chemicals. These include heavy metals, vinyl chloride, arsenic, formaldehyde, hydrogen cyanide, and carbon monoxide amongst thousands of others.
The chemicals are highly concentrated in SHS when compared to the smoke that smokers inhale.
Studies reveal that exposure to second-hand smoke in adults is associated with a greater risk of cognitive impairment.
While looking into smoking and dementia, second-hand smoke may increase the risk of dementia indirectly because of the aggravating risks that relate to the disease.
SHS causes several vascular changes including the formation of lesions, carotid artery thickening, compromised endothelial function, platelet aggregation, and it may also lead to stroke.
These vascular changes have been known to increase the risk of dementia.
More studies, however, need to be conducted to establish the link between dementia and SHS.
Research that Finds No Link between Smoking and Dementia
While many studies ascertain that smoking increases the risk of dementia, some strongly state that smoking is not related to dementia risk.
One of the studies that support this observed 531 seniors for more than a decade.
The researchers did not find any link between elevated dementia risk and tobacco smoking.
The study was conducted at the University of Kentucky and the researchers said that they used a different method known as “competing for risk analysis” to analyze data.
At baseline, the experts recorded that no participant was cognitively impaired.
During that time, 231 participants were former smokers while 49 were current smokers. After follow-up 111 subjects got a positive dementia diagnosis. 242 persons also passed on without dementia.
Their analysis revealed that smoking led to early death and that smoking was not associated with dementia.
The experts, however, acknowledged that because the study only looked at individuals from a single research center, the results may not necessarily represent other populations.
Why Research on Smoking and Dementia is Complex
Despite researchers carrying out a multitude of studies trying to connect smoking and the risk of dementia, it remains complex for various reasons like:
1. Many studies will not have accurate data because the researchers will focus on comparing individuals and their smoking habits at certain points in their lives.
A person may not be able to tell how much they smoked at that point especially if they have already started to develop some dementia symptoms.
It may help if researchers commit to following a large group of people over a long time recording their smoking habits to collect accurate data.
2. Cigarette smoke contains different toxins and chemicals making it hard to identify the one that is causing the damage. Some experts strongly believe that one of them (nicotine) helps to reduce dementia risk.
3. Some lifestyle risk factors for dementia may be challenging to separate.
For instance, many individuals who smoke also consume alcohol which is another dementia risk factor.
4. Smoking has been documented as one of the leading causes of premature death. A majority of smokers will most likely breathe their last breath before dementia starts to develop.
This implies that smokers who live to be older may have certain traits such as genetics that may not be a true representation of the entire population.
5. Some studies that have reported protective tobacco effects were influenced by players in the tobacco industry.
Closing Thoughts
Because there is still no cure for dementia, it is important to focus more on prevention by changing some of the modifiable risk factors like smoking.
Research on smoking and dementia shows that there may be a decrease in the dementia burden in future years if there will be a decrease in smoking.
More research needs to be done to give out a final stand on whether smoking increases the risk of dementia or not.
