Yoo Jae-suk says he quit smoking cold turkey after 20 years — and research suggests that may be the better way

Broadcaster Yoo Jae-suk, 54, has said he was once a smoker and has now been tobacco-free for about 20 years. He said he initially tried cutting back gradually but found it too difficult, and ultimately chose to quit all at once.

Yoo shared his experience on the tvN program "You Quiz on the Block," saying he had smoked in the past and had been quit for 20 years. He said his first attempt involved limiting himself to five cigarettes a day, but that approach did not work. He eventually decided to stop entirely in one go rather than tapering off.

The longer a person smokes, the greater the risk of developing various diseases, making early cessation all the more important. But for smokers who have developed a nicotine dependence, quitting is not simply a matter of willpower — it requires overcoming physical withdrawal symptoms while also changing deeply ingrained lifestyle habits.

Cigarette smoke contains thousands of chemical compounds — including nicotine, tar, carbon monoxide, formaldehyde and benzene — many of which are toxic or carcinogenic.

Harmful substances inhaled during smoking do not stay in the airways and lungs; they enter the bloodstream and travel throughout the body. The effects of smoking therefore extend well beyond lung disease.

In the respiratory system, cigarette smoke repeatedly irritates the airways and lung tissue, triggering inflammation and reducing lung function. Long-term smoking can cause chronic cough, phlegm and shortness of breath, and raises the risk of chronic obstructive pulmonary disease (COPD). It also weakens the airways' natural defenses, increasing vulnerability to infection, and lung cancer is one of the diseases most closely linked to smoking.

The heart and blood vessels bear a burden as well. Carbon monoxide binds to hemoglobin in the blood, reducing its ability to carry oxygen, while other harmful compounds in tobacco damage the inner walls of blood vessels and promote inflammation.

Nicotine stimulates the sympathetic nervous system, accelerating the heart rate, raising blood pressure and constricting blood vessels. Repeated exposure can accelerate the development of arteriosclerosis and increase the risk of cardiovascular and cerebrovascular conditions such as heart attack, angina and stroke.

According to the WHO, smokers face two to four times the risk of coronary artery disease and stroke compared with non-smokers.

Research suggests that quitting all at once, as Yoo did, may be more effective for some people than tapering off.

A research team at the University of Oxford in the United Kingdom compared quit rates among 697 adult smokers based on their cessation method. One group stopped smoking entirely on a set quit date, while the other reduced their smoking by about 75 percent over the two weeks leading up to that date before stopping.

After four weeks, 49 percent of those who quit abruptly had remained smoke-free, compared with 39 percent of those who cut back gradually. The same pattern held at six months, with rates of 22 percent and 15.5 percent, respectively.

The researchers said the process of gradually reducing cigarette consumption may itself have added an extra burden for some smokers, potentially making it harder to complete the final transition to full cessation.

Because nicotine dependence and smoking habits vary from person to person, finding a strategy that suits the individual is important. For those who find it difficult to quit on their own, seeking professional help from the outset is also an option.

In the early stages of quitting, one of the biggest challenges is riding out sudden, intense cravings. According to the Mayo Clinic, cravings typically ease within a few minutes even when they feel overwhelming.

When the urge to smoke strikes, waiting about 10 minutes and redirecting attention to another activity can help. Options include drinking water, chewing sugar-free gum, taking a short walk or simply getting up and moving around.

It also helps to identify situations that typically trigger the urge to smoke — such as drinking coffee or alcohol, or right after a meal — and to plan alternative behaviors in advance.

During the quitting process, nicotine withdrawal symptoms may appear, including irritability, anxiety, difficulty concentrating, insomnia, increased appetite and mood changes. For those who repeatedly relapse or find that these symptoms interfere with daily life, smoking cessation counseling and behavioral therapy are available.

Quitting smoking is not simply a matter of getting through each day without a cigarette — it is a process of overcoming nicotine dependence while changing lifestyle habits at the same time. Even after multiple failed attempts, trying again remains an option, and the chances of success improve when a person finds the right approach and makes use of professional support.