Addictive, yes, but otherwise nicotine was until recently considered the least harmful ingredient in tobacco.
Now some experts are beginning to question whether nicotine is actually as harmless as thought, or whether its harmful effects have simply been masked by the fact that other toxins in cigarettes are so much worse.
And that also raises questions about e-cigarettes – the “safer” alternative to cigarettes – as they often also contain nicotine.
Scientists have begun to look at nicotine because while smoking is at its lowest level since records began (in the 1940s), vaping is on the rise.
More than 270 people die every day in the UK from smoking-related diseases such as heart attacks, lung disease and cancer.
This toll is largely due to a toxic mix of harmful chemicals in cigarettes.
Otherwise, nicotine was until recently considered the least harmful ingredient in tobacco (archive image)
These include 1,3-butadiene (used to make rubber and can cause certain blood cancers); Cadmium (found in batteries and linked to lung cancer); and Chromium VI (used to make paints and dyes, also linked to lung tumors).
In fact, there are thousands of harmful chemicals in cigarettes – some occur naturally in the tobacco plant, others are added during manufacturing to enhance the flavor or increase the absorption of the smoke in the lungs (to release more into the bloodstream and then into the… brain). better 'hit').
But the innocent reason for tobacco's deadly effect on human health has always been considered to be nicotine – the addictive ingredient that produces the “high” that smokers crave, but that is considered relatively safe.
However, the increasing popularity of e-cigarettes has brought it into the spotlight because it gives users the same nicotine hit as tobacco without exposing them to harmful chemicals – although there are separate concerns about the possible carcinogenic effects of gases called volatile organics Compounds exist in e-cigarettes.
More than four million people now smoke in the UK and recent estimates suggest the number of e-cigarette users will surpass the number of smokers in the next few years.
As a smoking cessation tool, e-cigarettes are supported by charities such as the British Heart Foundation and Action on Smoking and Health. The NHS website states that e-cigarettes double the chance of quitting smoking compared to nicotine gum or nicotine patches.
Nicotine occurs naturally, but in small amounts, in many plants – including tomatoes, potatoes and eggplant. But concentrations are highest in tobacco plants, where it acts as a built-in insecticide.
Its effect on the brain is well known – within 20 seconds of inhalation, it triggers the release of chemical messengers such as dopamine, which are associated with reward and pleasure. But it also increases heart rate and blood pressure and causes blood vessels to constrict. Nicotine triggers the release of the hormone adrenaline. The big question is whether there are long-term effects.
“Nicotine actually has physiological effects on the body,” says John Britton, professor of epidemiology at the University of Nottingham and former chair of the Tobacco Advisory Group of the Royal College of Physicians. “It changes blood pressure and heart rate and has similar effects to caffeine.”
The problem was the lack of evidence on nicotine alone.
According to Professor Britton, one of the few large-scale studies to specifically examine the effects of nicotine was led by scientists at the Karolinska Institute in Sweden, who examined data from more than 130,000 men who regularly consumed snus.
This is a tea bag-style tobacco product that is placed under the upper lip to allow nicotine to enter the bloodstream through the tiny blood vessels on the inside of the mouth. (Snus is very popular in Scandinavia and although its sale is banned in the UK, its use is not illegal.)
The study results found that regular snus users were no more likely to have a heart attack than non-users, the European Journal of Epidemiology reported in 2012.
But now newer research – by another team of scientists at the Karolinska Institute – is calling these results into question.
The researchers examined the effects of snus on the arteries of otherwise healthy men. They did this by temporarily cutting off blood flow to the forearm after ingesting the snus and then measuring how much the arm “shrank” before allowing the blood to flow again to see how quickly the arm returned to its original diameter . The faster this happens, the more stretchy the arteries are.
The researchers found that the nicotine from snus made the arteries much stiffer – reducing blood flow and potentially increasing the risk of heart disease down the line, according to findings published in the journal PloS One in June last year.
Some experts are beginning to question whether nicotine is really as harmless as thought, or whether its harmful effects have simply been masked by the fact that other toxins in cigarettes are so much worse
Other studies suggest that the incidence of peripheral arterial disease (restricted blood flow in the legs and feet) from nicotine exposure from snus is comparable to that from cigarette smoking.
In September, the British Professional Football Association announced an investigation into reports of increasing snus use – top football players were reportedly spotted using snus – and warned that it was linked to heart problems and reduced physical performance.
Separately, research presented at the American Heart Association conference last October showed that e-cigarette users who were regularly exposed to nicotine consistently performed worse than non-vapers in treadmill tests used to predict heart disease risk – with similar harmful effects to cigarettes.
Laboratory studies also suggest a possible link to some types of cancer.
HOW TO COMPARE LEVELS
While some vaping devices are nicotine-free, others contain 10 or 20 milligrams per milliliter of liquid – meaning a standard 2ml vape can contain around 40 mg of nicotine; this corresponds to one to two packs of 20 cigarettes.
However, it is highly unlikely that users will consume an entire vape at once.
It's estimated that taking about 15 puffs from an e-cigarette delivers the same amount of nicotine as a cigarette – although studies suggest vapers inhale for twice as long, potentially giving them a higher dose of nicotine.
Nicotine gum and patches deliver a much smaller dose of nicotine – patches come in different sizes, but a 21 mg patch contains the same amount as about 20 cigarettes.
However, since there is a sustained release of nicotine and not a sudden increase in nicotine, the risks are considered negligible.
For example, nicotine has been shown to promote the growth of pancreatic cancer cells in mice, while a 2021 study at the Wake Forest School of Medicine in the US found that nicotine promotes the spread of breast cancer cells to the lungs, improving the environment in the Lung alters airways to promote tumor growth, the journal Nature Communications reported.
Dr. Marina Picciotto, a neuroscientist at Yale University, has studied the effects of nicotine on the brains of young adults and is particularly concerned about the exposure of young vapers during their crucial years of neurocognitive development.
She told Good Health: “We know from both preclinical and human studies that nicotine disrupts normal activity in the brain” – particularly in areas associated with memory, learning, attention and arousal.
According to Action on Smoking and Health, almost one in 20 children in the UK aged between 11 and 15 regularly smoke e-cigarettes, rising to around one in six of older teenagers.
Activists fear that the fact that some e-cigarettes are designed to attract young palates, with flavors like blackberry sour, means a new generation is being exposed to nicotine.
Dr. Picciotto says that while nicotine may be less harmful than other toxins in tobacco, “my concern is that we won't know more about the consequences of nicotine vaping for years to come – just as the consequences of smoking can take decades.” become visible.” .
But Professor Britton says the risks are minimal.
“Being addicted to nicotine for life is probably like drinking coffee every day.” There is little evidence that it causes serious illness, and in humans it is still caused by tobacco and the many in smoke substances contained in it.
“The real harm comes from the stuff you have to take with you to get the effect – toxins in tobacco and the other chemicals in e-cigarettes.”
“If one of my kids said they were going to start vaping, I would say, 'No, because of my dead body' – why would I get addicted to something unnecessarily?” But if they said they were vaping instead of smoking , I would say “yes, absolutely” – that’s a given.”
Do I really need…
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CLAIM: A chest strap heart monitor that “accurately records continuous ECGs for up to 24 hours,” says the manufacturer. Aimed at people who exercise a lot to “ensure they don’t put too much strain on the heart through exercise.”
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EXPERT VERDICT: “Doctors use EKG machines to check for arrhythmias – irregular heartbeats – and for signs of heart disease,” says family doctor Dr. Nisa Aslam. “This product appears to be aimed at athletes so that they can work to their limits for maximum fitness without risking damage to their heart.” I can certainly see how it would be a useful addition to a training program in these circumstances.
“It can also help detect conditions such as atrial fibrillation.” [a rapid and irregular heart beat]which many people have without realizing it and which can lead to strokes.
“However, the manufacturer states that this is not a medical device and is not intended for medical diagnosis. Therefore it is unlikely to be as reliable as a hospital ECG. “It is also incredibly expensive.”