When a person smokes, a dose of nicotine reaches the brain within about ten seconds. At first, nicotine improves mood and concentration, decreases anger and stress and relaxes muscles.
The reason behind this is that there are a large number of nicotine receptors in the brain and nicotine influences a wide variety of cognitive domains such as sensorial, motor, attention, executive function, learning and memory.
For smokers, there are two different neurobiological mechanisms in play here. Firstly, they learn that smoking temporarily increases their cognitive functioning by improving some components of attention and memory. As a result, they smoke more to keep their cognitive performance above normal levels not realising that regular doses of nicotine lead to changes in the brain. Secondly, if they stop smoking, this causes significant cognitive disruption and disorientation due to their nicotine dependence.
It’s a vicious circle and one that really has to be broken.
Dementia and tobacco
In 2014, the World Health Organization (WHO) published a report entitled "Tobacco Use & Dementia," based on a comprehensive scientific review of tobacco use, exposure to second hand smoke, and incidence rates for all types of dementia, including Alzheimer’s
The report found that smokers have a 45 percent higher risk of developing dementia than non-smokers, and concluded that 14 percent of all Alzheimer's cases worldwide may potentially be attributed to smoking.
Smoking is thought to cause dementia by the same biological mechanisms as its contribution to coronary artery disease cerebrovascular disease, and stroke, namely by promoting the following three pathological processes:
Is second-hand smoke a risk?
A link between second-hand smoke and dementia is very likely, although studies are limited. The report cites six studies that all suggest exposure to second-hand smoke increases the risk for Alzheimer's disease and other types of dementia. The risk appears to be "dose-dependent"—related to the frequency and duration of exposure. Even less is known about smokeless tobacco use and dementia risk.
As with many other factors affecting cognitive health, smoking is a lifestyle choice although admittedly a very hard one to give up once hooked. Greater awareness about the risks involved may help incentivise smokers do just that.
Cognitive Health Check is an independent source of information and news about cognitive health.