It has been more than 100 years since humans discovered the health hazards of smoking, and it has been 55 years since the first report on smoking and health was released by the chief health officer of the United States in June 5438+0964 65438+ 10/0/. A great deal of evidence shows that smoking is the single preventable factor that has done the greatest harm to human health since the 20th century.
However, today, there are still people who have doubts and doubts about the health hazards of smoking.
Looking back at the process of human understanding of the harm of smoking, 19, with the invention of cigarette machines and aggressive advertising by manufacturers, smoking quickly became popular all over the world.
Soon, people discovered the harm of smoking to public health, which attracted the attention of scientific and medical circles at the beginning of the 20th century.
In June 1957, after the accumulation of evidence about the adverse effects of smoking in 1930s, 40s and 1950s, Leroy E. Burney, the chief public health officer of the United States, first released the official position of American public health department on smoking, saying that the evidence showed that there was a significant causal relationship between smoking and lung cancer.
The firm urging of several well-known private health organizations has become the final official report on smoking and health hazards in the United States.
196 1 In June, the American Cancer Society, the American Heart Association, the American Tuberculosis Association and the American Public Health Association jointly sent a letter to President Kennedy at that time, calling for the establishment of a national committee on smoking, striving to "seek" a plan to interfere with the tobacco manufacturing industry and individuals' freedom to smoke to the greatest extent, and finally solve the health problems caused by smoking.
1On June 7th, 962, the President appointed a new chief public health officer, Luther L. Terry, and convened an expert committee to conduct a comprehensive review of the scientific literature on smoking.
From 1962 1 1 to 1964 1, with the assistance of more than 150 consultants, the committee has reviewed more than 7,000 scientific literatures on smoking and health.
Finally, Terry released the report on smoking and health made by the Committee on June 65438+1October 65438+1October 665438+1October 0.
The report hit the whole United States or even half the world like a blockbuster, and became the annual headline news of 1964 in the United States.
In order to minimize the impact of the news on the stock market, it was specially released on a Saturday.
The harm of smoking to health
The report clearly points out with strong evidence that smoking is:
The main causes of lung cancer and laryngeal cancer in men
Possible causes of female lung cancer
The most important cause of chronic bronchitis
Specifically, the report estimates that compared with non-smokers, the risk of lung cancer is 9 to 10 times higher on average, and the risk of heavy smokers is at least 20 times higher. With the extension of smoking time, the risk further increases; After quitting smoking, the risk will be reduced.
The report believes that smoking is the most important cause of chronic bronchitis, and points out that smoking is related to emphysema and coronary heart disease.
At the same time, the report also pointed out that smoking during pregnancy will reduce the average weight of newborns.
The report's fly in the ointment is the lack of understanding of nicotine addiction, which insists that "smoking should be defined as a habit rather than an addiction".
In fact, this report claims that the scientific and medical circles have reached the broadest knowledge that smoking is harmful to health.
Based on this report, the tobacco control movement has been gradually launched in the United States and even around the world. For more than half a century, it has made remarkable achievements-the smoking rate in western countries has been greatly reduced, and the resulting health hazards, including the reduction of mortality, have also been fully reflected.
So far, the accumulated evidence proves that the harm of smoking to human health and life expectancy is much higher than the original estimate.
Evidence shows that the harm of smoking to health involves all organs of the whole body. These include:
Smoking is the biggest single preventable cause of human cancer, which can lead to cancer in 15 parts of the whole body.
Smoking is one of the main preventable risk factors for the increase of cardiovascular diseases.
Smoking is the main risk factor of chronic obstructive pulmonary disease.
Tobacco is the most addictive psychotropic drug in the world, which can lead to serious dependence, withdrawal symptoms and other mental problems.
Smoking during pregnancy is the main cause of adverse reproductive consequences and mental problems of children.
Smoking is closely related to the increased risk of accidental death.
Smoking causes obvious tooth damage.
Smoking is also closely related to diabetes, overall health decline, eye disease, hip fracture, liver cirrhosis, low bone density, peptic ulcer and so on.
How to explain the phenomenon of long-lived smokers?
Whenever talking about the harm of smoking to health, some people always cite some examples of "longevity" smokers, trying to erase the harm of smoking, so as to find rationality for their smoking behavior, thinking that "ignoring someone's face will make others speechless."
Don't you know that their complacency is essentially an extremely stupid logical error called "survivor bias"?
Survival deviation
Survivor bias means that when people make judgments and decisions, they only pay attention to the individuals or things they have chosen through a certain selection process, and intentionally or unintentionally ignore or forget those people or things that have not been paid attention to. Usually, due to the halo effect, people tend to pay attention to individual successful examples and ignore more failed examples, resulting in cognitive bias.
The most famous real example of survivor bias is that in World War II, the military almost made a mistake in the decision to install protective armor for American bombers.
In World War II, American bombers have been the key targets of the other side while causing serious blows. Many bombers were hit or even destroyed, causing heavy losses to bombers and crew.
In order to reduce losses, the US Air Force urgently needs to improve the aircraft, install protective armor and increase the return rate.
But where is the armor installed on the plane?
According to the distribution of bullet holes in the fuselage of the returning aircraft shown in the above picture, the US Air Force believes that reinforced armor should be installed in the parts with dense bullet holes.
However, Abraham Wald, a statistician, thinks that the idea of the Air Force has made a low-level mistake of survivor bias.
Because the air force only paid attention to the plane that successfully returned, but ignored the plane that was hit and crashed.
He believes that the bullet holes are dense, which is "a place where bombers can return safely even if they are hit." The key parts of the return capsule that are not damaged may be places that need extra protection, such as the engine.
Because once these parts are hit, the plane is likely to crash and cannot return.
That's probably why those destroyed planes didn't come back.
In this example, statisticians helped the US Air Force avoid a lot of losses by considering the prejudice of survivors.
A long-lived smoker, another typical example of survivor deviation.
"Long-lived smoker" is another example most often cited by scientists when introducing the deviation of survivors. After the US military returned to the bomber:
The bullet holes on the returning plane are like the tobacco smoked by long-lived smokers all their lives and the health hazards they cause. Although it caused a major blow, it only escaped the "crash" because it did not hit the fatal target.
Moreover, more and more smokers die early because of being hit in the vital parts-this is an indisputable fact that the mortality rate of smokers is much higher than that of non-smokers in epidemiological research.
The average life expectancy of long-term smokers is 10 years old.
As early as the first report of 1964, there was scientific evidence that compared with non-smokers, the death rate of long-term smokers increased by 70%, which was 1.7 times that of non-smokers.
According to the evidence accumulated by the CDC in the United States for many years, combined with the age-standardized mortality rate in the United States, it is calculated that the average premature death of long-term smokers compared with non-smokers is 10 years, which is equivalent to smoking a cigarette 13.8 minutes and a pack of cigarettes for 4.6 hours.
A new large-scale study in Australia once again confirmed the conclusion that smoking will reduce the average life expectancy of 10 years.
Some people take a few long-lived smokers as examples, which makes them lack statistical concepts.
How can we truly and accurately reflect the relationship between smoking and health?
We should not only look at a few long-lived smokers or smokers who died early, but should take the results of large-scale population-controlled studies as the basis to eliminate the influence of various deviations on the results as much as possible.
For decades, there have been countless such studies around the world, and the most recent one is from Australia.
20 15 A prospective study in Australia based on 200,000 people aged 45 and over in New South Wales (part of a long-term study of large-scale people aged 45 and over in Australia) shows that although the smoking rate in Australia has dropped significantly,
However, due to the long-term lag of the influence of smoking, the high smoking rate in the past is still the main cause of population death at present.
The results show that compared with non-smokers, the average death rate of smokers has increased by nearly three times.
The mortality rate increases with the increase of smoking intensity. Compared with non-smokers, the mortality of those who smoke ≤ 14 cigarettes a day (average 10 cigarettes a day) and those who smoke ≥25 cigarettes are increased by 2 times and 4 times respectively.
In the past, among smokers, with the extension of quitting time, the mortality rate gradually decreased, and there was no significant difference between those who quit smoking before the age of 45 and those who never smoked.
It is estimated that the average death time of smokers is earlier than that of non-smokers 10 years.
Long-term smoking reduces the average life expectancy by 65,438+00 years, which is highly consistent with many other research conclusions about the health hazards of smoking, which fully proves the credibility of this conclusion.
In short, the average life expectancy of long-term smoking is 10 years old, and the evidence is conclusive and unshakable.
Some people deny the harm of smoking by the phenomenon that individual smokers live longer, and make the logical mistake of survivor deviation.
Source: Zhihu Daily.