Quitting smoking before the age of 50 gives you a better chance of avoiding lung cancer than quitting after 50, a study has suggested.
Researchers from Korea studied more than 2.9 million people and found that people who stopped smoking had a 17 percent lower risk of all types of cancer compared with those who did not quit smoking.
Smoking is known to be contributing factor for multiple cancers, including lung, stomach, colorectal, liver, pancreas and kidney.
Cigarettes increase cancer risk because poisons in cigarette smoke can weaken the body’s immune system, which makes it harder to kill cancer cells.
Smoking is known to be contributing factor for multiple cancers, including lung, stomach, colorectal, liver, pancreas and kidney
The researchers looked at Koreans aged 30 and older who had two or more consecutive health checks under the National Health Insurance Service in 2002 and were followed until 2019.
They checked if participants had developed cancer using cancer registry data.
Of the 2.97 million participants, there was an average follow-up of 13.4 years, during which time 197,000 cancer cases were confirmed.
For approximately seven years after stopping smoking, the researchers saw an increase in cancer risk. This may be because those individuals had already accumulated substantial damage due to smoking, known as ‘sick quitters’
For approximately seven years after stopping smoking, the researchers saw an increase in cancer risk.
This may be because those individuals had already accumulated substantial damage due to smoking, known as ‘sick quitters.’
This means they did not become ill from stopping smoking, but stopped smoking because they got sick.
Compared with those who did not quit smoking, people who completely quit had a 17 percent lower risk of cancer.
Participants’ cancer risk remained elevated for 10 years after quitting, but after 15 or more years, the risk had halved.
Lung cancer risk was the first to go down, decreasing three years earlier than other cancers.
Quitting before the age of 50 was associated with a 57 percent reduction in lung cancer risk compared with quitting at age 50 or older.
Stopping smoking provided a 42 percent risk reduction for lung cancer, 27 percent for liver, 14 percent for stomach and 20 percent for colorectal, compared to continuing to smoke.
The study was published in the journal JAMA Network Open.
Lung cancer is the leading cause of cancer deaths in the US. It accounts for one in five cancer deaths, followed by colorectal cancer, which causes one in 10 cancer deaths.
Roughly 238,000 new cases of lung cancer are diagnosed every year in the US – and 127,000 people die from the disease, according to the American Cancer Society.
There are two main types of lung cancer: small cell and non-small cell.
Non-small cell lung cancer is the most common type, accounting for nine out of 10 lung cancer diagnoses, and typically grows more slowly. It usually doesn’t cause any symptoms until it has progressed.
Signs of non-small cell lung cancer, according to the NCI, include chest pain or discomfort, a lingering cough, trouble breathing, wheezing, coughing up blood, loss of appetite, unintentional weight loss, fatigue or lethargy, trouble swallowing, and swelling in the face or veins in the neck.
Cigarette smoking is the leading cause of lung cancer.
In 2021, an estimated 11.5 percent of US adults smoked cigarettes, which equates to 28.3 million people.
According to the charity Cancer Research, when you smoke, cigarettes release more than 5,000 different chemicals.
These harmful chemicals enter the lungs and damage DNA.
DNA is in charge of how our cells grow and behave. Damage to DNA causes cells to act in ways they are not supposed to. A build-up of DNA damage over time can lead to cancer.
Other chemicals make it more difficult for cells to repair DNA damage, which can cause cancer.
A study in 2004, that followed up a 50-year study of British doctors, found that if smokers quit before the age of 30, they can avoid more than 90 percent of the risks of lung cancer caused by smoking.
Smoking also has an effect on other cancers, experts believe smoking causes at least 15 types of cancers.
It can be the cause of mouth and throat, rectum, liver, and pancreas cancer to name a few.