Today I hope to give you an insight into one of the most stigmatized stimulants, the one and only Nicotine.
For the last few decades successful anti-smoking campaigns have lumped cigarettes, a cocktail of harmful chemicals paired with a social experience, with nicotine, a neuroactive compound that occurs naturally in tobacco.
At the outset I would like to stress that this article does NOT in any shape-or-form support smoking or consuming tobacco!
The purpose of this article is to examine whether there are any benefits or adverse effects for utilising isolated nicotine to enhance cognitive performance.
In a nutshell:
- Nicotine has a significantly different effect on the human body when isolated from cigarette smoking.
- Nicotine has been shown to improve selective attention, sustained attention, and decrease distraction. It also seems to affect pre-attentional processing – the unconscious accumulation of information from the environment. A recent meta-analysis founds significant positive effects of nicotine on fine motor skills, short-term episodic memory accuracy, orientating attention reaction time and working memory.
- The potential risk associated with acute use of nicotine is predominantly mediated by vasoconstriction (narrowing of blood vessels) and hypertension (high blood pressure) in susceptible individuals (those with pre-existing heart/vascular disease).
- Nicotine is NOT classified as a carcinogen (substance capable of causing cancer), and there are no epidemiological studies that link stand-alone nicotine and formation of cancer.
- New evidence suggests that there may be use for nicotine in mild cognitive decline in the older demographic, preventing and treating Alzheimer’s dementia, treating Parkinson’s disease, schizophrenia and ADHD.
One of the main reasons tobacco smoking became popular in the 17th century, was that nicotine is a powerful stimulant. Since then, nicotine consumption has been widespread, mainly from tobacco smoking, and is unique in that its use has not diminished over time or culture, regardless of other recreational drugs or drugs of addiction.
Professor Michael Russell wrote in the BMJ in 1976 “People smoke for nicotine but they die from the tar“, and we now know that the smoke inhaled from cigarettes contains over 7000 chemicals, many of which are responsible for the detrimental effects on human health.
Undoubtedly, nicotine contributes to some of the addictive potential of smoking, via a dopaminergic cascade released in the brain (which is present in most drugs of addiction). However, independent nicotine consumption has been shown to be far less addictive than smoking cigarettes, as other constituents in smoking have been found to be major contributors to this problem. This has been investigated in both human and animal populations. How many people do you know that have become addicted to nicotine gum or patches? My bet is that it is few and far between.
From my reading it appears that nicotine is addictive, but it is vastly overstated.
The medium for consuming nicotine has been found to have a dramatic effect on the addictive potential.
The faster the nicotine is able to get through the blood brain barrier, and cause the cascade of neurotransmitter release, the stronger the reinforcement of the behaviour. Smoking e-cigarette represents the highest addiction potential (other than smoking cigarettes), as it causes the fastest crossing of nicotine into the brain (5-10 seconds – which is faster than intravenous administration!). A step down from this is oral nicotine mediums such as gums, and a further step down is the transdermal route such as patches.
How it works
Nicotine mimics the neurotransmitter acetylcholine, binding to nicotinic acetylcholine receptors in the brain, causing a cascade of neurotransmitters to be released (This includes acetylcholine, dopamine, serotonin, glutamate), which is thought to be responsible for the aforementioned cognitive effects.
Circulating nicotine also activates the sympathetic nervous system, causing the adrenal medulla to release adrenaline. This leads to an increased heart rate, blood pressure, increased circulating blood sugar levels, and also underlies some of the increase in attention and focus.
Higher adrenaline levels also increase the body’s metabolic rate and suppress appetite. This, in addition to nicotine’s ability to directly stimulate lipolysis (breakdown of fat), may stimulate weight loss in some users.
The half-life of nicotine (time taken for half of the nicotine to be cleared from the blood) is 1-2 hours, but its active metabolites hang around for much longer.
Although nicotine is not classified as a carcinogen, it may be indirectly involved in the progression of cancer growth (once a cancer is already established). Also, studies have suggested that some people metabolize nicotine to nornicotine and then into N′-nitrosonornicotine (NNN), a substance which appears to have carcinogenic potential. Nicotine patch users have had relatively low urinary levels of NNN and a confounding factor in the study that could explain this is that 40% of participants were exposed to second-hand smoke. At least one study failed to find an increase in urinary NNN in a cohort of nicotine users (non smokers).
As mentioned previously, nicotine has significant effects on the cardiovascular system (vasoconstriction and hypertension), mainly through the action of adrenaline . In people with cardiovascular or vascular disease, these effects may be problematic.
Chronic regular nicotine use may predispose some individuals to cardiac and vascular disease. Nicotine should also not be used during pregnancy, as it increases the rate of birth defects.
The research I found on this topic spurred me to give the nicotine gums a go. I have found a noticeable difference in my level of motivation, attention, processing speed and productivity using nicotine, which has been of use for mentally demanding activities (such as writing this article :p). On the other hand, not everyone will love the feeling of having a wave of adrenaline hit your system; I certainly have found it a bit intense at times when I haven’t got my dose right.
This article first appeared on PRYMD.com