It is said that smoking hurts the body, and most people must know this truth.
Although the occurrence of cancer is not caused by a specific factor, the same is true for lung cancer, although it is related to environmental factors, occupational exposure, chronic respiratory diseases, genetic factors, etc.
But smoking is still the biggest carcinogenic factor for lung cancer.
According to the data, more than 90% of lung cancer in most countries in the world is caused by smoking, and 35 people in every 100,000 people on the mainland have lung cancer. The most important thing is that the earlier the smoking age, the higher the incidence and mortality rate of lung cancer.
According to WHO, 85%-90% of deaths from lung cancer can be attributed to smoking, and nearly 6 million people die each year worldwide from smoking and second-hand smoke.
How harmful is smoking to the body?
It should be known that the composition of tobacco is very complex, the main active substances are nicotine, tar, carbon monoxide, etc., its chemical substances as many as 7,000 species, harmful ingredients up to more than 4,000 species, of which more than 400 kinds of carcinogens.
There is evidence that smokers have a significantly higher rate of lung cancer than non-smokers, and smoking 20 cigarettes a day increases the risk of lung cancer by about 10 times.
Not only that, but people who inhale secondhand smoke for a long time also have a higher risk of lung cancer than normal people, resulting in most smokers living a shorter life than non-smokers.
In particular, the average life expectancy of smokers who smoke 25 cigarettes per day is 5 years less than that of non-smokers, or even longer.
Smoking is harmful to health, why do many smokers not get lung cancer?
Speaking of this, many people will begin to refute: it is said that smoking can lead to lung cancer, why do some smokers around them for decades, or live well?
For this question, a study published in Nature Genetics on April 11 found that:
The reason why some smokers are not prone to lung cancer may be that they themselves have a strong mechanism to avoid lung cancer by restricting mutations.
Simon Spivack, a professor at the Albert Einstein School of Medicine in the United States, and other researchers conducted experiments on this, recruiting two groups of non-cancer patients who were undergoing bronchoscopy to participate in the experiment.
One group consisted of 14 people aged 11-86 who never smoked;
The other group consisted of 19 people aged 44-81 years who smoked up to 116 packs per year (1 pack of years equals one pack of cigarettes per day for 1 year) and compared the normal lung epithelial cell mutation profiles of the two groups of participants by SCMDA.
The researchers found that the number of mutations in lung cells would theoretically rise as the smoking age increased, but interestingly, after 23 packs, the increase in cell mutations suddenly stopped.
In this regard, the researchers analyzed and found that such people can survive for a long time when smoking a large amount, and the most important thing is that they can successfully inhibit the accumulation of further mutations.
The main reason why mutations are leveling off is that their human systems are able to skillfully repair DNA damage and eliminate cigarette smoke toxins.
Of course, such people are a minority after all, and do not represent authority, smoking is still a high risk factor for lung cancer.
The reason why those old smokers live a long life is more or less "special"
Although smoking is harmful to health, this does not indicate that there is an absolutely inevitable link between smoking and longevity.
After all, there are many reasons that affect people's life expectancy, such as genetics, social environment, natural environment, psychological state, eating habits, living habits, sports and fitness, medical care, etc., rather than relying on whether to smoke or not.
People who smoke and drink for a lifetime and live a long life, their family members tend to live a long life, which is determined by the genetic "longevity factor".
Some people are born with longevity genes, so smoking can also live a long life.
But there are too few such people, even if they gain a long life, these people will be invaded by bronchitis, rhinitis, laryngitis and other diseases, so that the body suffers a lot.
Just as the so-called: genes are destined, hard work is not enough, this kind of natural "good luck" can not be learned.
For us ordinary people, we need to understand that smoking is certainly not good for health---- and staying away from tobacco is the way we must choose to live.
Therefore, before determining whether you are talented, it is better to treat yourself as an ordinary person.
bibliography:
【1】Single-cell analysis of somatic mutations in human bronchial epithelial cells in relation to aging and smoking.