A large population study in South Korea shows that quitting smoking reduces the risk of cancer for years after quitting. It remains best to stop as early as possible. Especially for lung cancer.
Smoking is one of the leading causes of cancer worldwide. According to the World Health Organization (WHO), smoking is responsible for approximately 22% of all cancer deaths. That’s because smoking damages the cells’ DNA and causes mutations that can lead to uncontrolled cell growth. Smoking therefore increases the risk of various types of cancer, including lung, stomach, colon, liver, pancreas, breast, cervical, prostate and bladder cancer.
Starting to smoke is therefore not a good idea, but what about the people who quit smoking? How long will it take for their cancer risk to decrease? And does it matter at what age they stop? Researchers at the Seoul National University College of Medicine to answer.
Population survey
To this end, they conducted a large-scale population survey in South Korea. They followed more than a million people aged forty and older for fifteen years – between 2002 and 2017. They collected data on their smoking status, age, gender, body weight, alcohol consumption, exercise and other factors. They also looked at whether the people had had cancer, and if so, what type.
Quit before the age of fifty
It showed that quitting smoking significantly reduces the risk of cancer compared to continuing to smoke. The effect was strongest for lung cancer, the most common and deadly form of cancer in smokers. People who stopped smoking had a 50% lower risk of lung cancer after ten years than people who continued to smoke. Quitting smoking before the age of 50 reduces the risk of lung cancer even more compared to people who quit after that. But quitting smoking also turned out to have a very beneficial effect on other forms of cancer. Such as stomach, intestinal, liver, pancreas, breast and prostate cancer. However, the effect was less strong than for lung cancer, and the age at which one stopped smoking made less of a difference to the risk of one of these types of cancer.
Korean smokers
The study is one of the largest and longest population-based studies into the link between smoking and cancer. It is no coincidence that the research was conducted in Korea. The Korean population has one of the highest smoking rates in the world. According to the WHO, almost half of Korean men and about 6% of Korean women smoked in 2018. Because this is not representative of the rest of the world population, the researchers want to expand the study and compare it with other population groups and cultures. The Korean population also has a high prevalence of chronic viral hepatitis and liver cirrhosis. At the same time, breast and prostate cancer is less common. All of this could influence the link between smoking and cancer. The researchers also want to include more types of cancer in their analysis, such as kidney, esophageal, mouth and throat cancer, which are also linked to smoking.
Stopping is still better
Although the research cannot be directly generalized to other countries, it remains established that quitting smoking significantly reduces the risk of cancer, even decades after quitting. The researchers therefore emphasize that it is never too late to stop – although, especially in the case of lung cancer, it remains best to stop before middle age. They hope that their findings will contribute to the prevention and control of cancer, and that they will motivate and help smokers to quit smoking.
Stopping earlier would be even better, according to previous research. It turns out that it is best to quit smoking before the age of 35. If you succeed, you will generally live as long as someone who has never lit a cigarette. “Quitting smoking before you reach the age of 35 is really life-saving,” researcher Blake Thomson said earlier in an interview with Scientias.nl. However, this does not mean that it is harmless to smoke until the age of 35 and only then stop, Thomson warns. “That is certainly not without consequences. Smoking affects the quality of life and causes a lot of damage to the body, even if it may not be fatal.”
2024-02-10 14:33:45
#late #quit #smoking #risk #cancer #gradually #decreases #quitting
