Want to quit smoking? Here's what the science says

Anyone who has tried to quit smoking will tell you how difficult it is. There's always the temptation to share a cigarette with a friend over a beer or to escape work for a quick "smoko," as they say in Australia.

Research studies suggest that 60-75% of people relapse in the first six months after trying to quit smoking.

As with other forms of addiction, quitting cigarettes is a difficult psychological battle. Social events, depression or simple daily habits can have you craving for one.

But the health benefits of long-term abstinence are huge.

Risks of stroke, coronary heart disease, cancers and overall health improve substantially in a matter of weeks or months after quitting smoking.

Smoking is one of the biggest killers, with around 14% of deaths worldwide attributed to smoking-related illnesses, according to World Health Organization data in 2019. Many of those deaths are attributed to rising smoking rates in lower and middle-income countries. And more recent studies show that to be an ongoing trend.

"Smoking is a massive global health burden. There will be a billion deaths globally in this century from smoking-related illnesses if we don't bring smoking rates down," said Hazel Cheeseman, deputy chief executive of Action on Smoking and Health (ASH), a UK-based public heath charity.

Why are cigarettes addictive?

When you smoke a cigarette the burning tobacco releases nicotine, which enters the blood via the lungs.

The nicotine gets pumped to the brain, where it activates receptors on the surface of neurons called nicotinic acetylcholine receptors.

Activating these receptors triggers the release of chemicals in the brain — neurotransmitters — such as dopamine.

The release of dopamine doesn't necessarily cause addiction. But when it acts in a specific part of the brain — where our so-called reward system lies — it can cause addiction. That part of the brain is called the mesocorticolimbic circuit.

And this is how the addiction works: When nicotine triggers dopamine release in the reward system, it induces a rewarding feeling, like a mini rush. Each cigarette you smoke reinforces this feeling, causing you to crave cigarettes and ultimately becoming addicted to them.

So, when we want to stop smoking, we have to break this link between cigarettes and the feeling of reward. It's tough. You'll need all the help you can get to make it work over the long term. But it is possible.

Interventions to stop smoking

There are two main methods to break the psychological attachment to cigarettes: willpower and self-discipline.

You can also use therapies to fulfil the nicotine cravings, but without the health problems associated with active smoking.

For therapies, there are three types. First, there are nicotine replacement therapies, such as patches, gums or inhalators (also known as inhalers) that slowly release nicotine, stopping the urge to smoke. Nicotine itself isn't harmful, but the smoke you inhale from cigarettes is.

Then, there are medications, such as varenicline and bupropion.

Varenicline promotes dopamine release in the reward pathway, mimicking the reward of smoking and reducing withdrawal symptoms from stopping smoking.

Bupropion works in a similar way but via a different neurotransmitter system known as GABA, the main neurotransmitter that dampens brain activity.

"Although medications are a more expensive treatment, they're enormously cost effective when you look at the impact of smoking on health and on health systems," said Cheeseman.

E-cigarettes — good or bad?

Electronic cigarettes have a strange reputation when it comes to giving up smoking. Are they even safe?

"There is good evidence that e-cigarettes can help you stop smoking. But they are a non-medically licensed product, so they're not administered as medication," said Cheeseman.

She said e-cigarettes are safe in the short to medium term, or, at least, less harmful than conventional cigarettes. But she added that "it's unlikely [vaping] products are risk-free in the long term."

Another concern is that e-cigarettes may create new addictions or act as a gateway to smoking tobacco. It's particularly worrying in younger people, with some evidence suggesting that teens who vape are more likely to smoke tobacco in the future.

Try everything to quit smoking, all at once

Which method works best to help you quit smoking?

The scientific consensus says that using multiple methods at the same time is your best bet.

A 2020 meta-analysis of more than 700 clinical studies found that combining several methods has the best results for helping people achieve sustained abstinence from cigarettes.

While all individual therapies were more effective than a placebo — essentially, doing nothing — it's when you combine them together that you really start to see results.

"The most effective way to stop smoking is with behavioral support that helps you create strategies to deal with the psychological side of cravings, [combined with] medications that help deal with the physical side effects of stopping smoking," said Cheeseman.

Everyone's pathway to quitting smoking is different — some can go cold turkey and quit on a whim, others need years of complimentary therapies. It might take a while to find your best method. The question is: how much do you want to quit?

Edited by: Zulfikar Abbany