The smoking rate among women is not high, so why is the lung cancer rate so high?

Lung cancer is the most common primary malignant lung tumor, the cancer with the highest morbidity and mortality, one of the malignant tumors that poses the greatest threat to human health and life, and is also the number one killer of women's health.

The top British Medical Journal (BMJ) published a retrospective analysis of the causes of death of a million people in China and found that 82% of men who died of lung cancer in my country were smokers, which is not surprising. However, 61% of female deaths were non-smokers. In rural areas where there are fewer female smokers, nearly 80% of women who died of lung cancer were non-smokers.

In most people's impressions, regular smokers are the main targets of lung cancer, while the proportion of female smokers is not high, so why is the harm so great? Because there are several other factors that are easily overlooked, which are no less harmful than smoking.

01 Smoking

It is common knowledge that smoking increases the risk of lung cancer. Smoking causes free radical oxidative damage and specific genetic changes in bronchial tissue, especially the deletion of the short arm of chromosome 3, which may be the main target of tobacco carcinogens.

More than 50% of smokers in my country are men, and the incidence and mortality of lung cancer are about twice that of women. But for women, the incidence of lung cancer is actually not low, and it is the second most common disease after breast cancer.

02 Secondhand smoke

Passive smoking is a problem faced by many women. Although they are not directly exposed to smoking, they still cannot escape the harm caused by tobacco. Cigarette smoke contains high levels of carcinogens, such as nitrosamines, 4-aminobiphenyl, and benzopyrene.

A meta-analysis of lung cancer in non-smoking women in my country found that the risk of lung cancer in women who are exposed to secondhand smoke during adulthood and throughout their lives is 1.2 to 1.5 times higher than that of women who do not smoke secondhand smoke. In addition, the harm of secondhand smoke is not limited to lung cancer, but also increases the risk of cardiovascular disease. If you live in the same room with smokers for a long time, you should pay attention.

03 Cooking Fumes

When the oil in the pot is heated to 170℃, it will begin to vaporize and decompose, forming oil smoke composed of 10μm small oil droplets; when the temperature rises to 270℃, the high-boiling point edible oil molecules begin to vaporize, and blue oil smoke appears.

Cooking fumes contain about 220 ingredients, including mutagens and carcinogens such as benzopyrene, volatile nitrosamines, and heterocyclic amine compounds. [3] Long-term exposure to cooking fumes may lead to diseases such as pharyngitis, rhinitis, and tracheitis, and in severe cases may induce lung cancer. Some epidemiological studies have confirmed that exposure to restaurant cooking fumes is associated with the incidence of lung cancer in the population, and significantly increases the risk of lung cancer in non-smoking women.

Not only that, cooking fumes can also cause cardiovascular diseases through oxidative damage and increase the concentration of low-density lipoprotein (LDL) in the blood. This component will deposit on the blood vessel wall, thus inducing cardiovascular diseases. It can also affect the health of the human nervous system and lead to poor sleep quality. Therefore, it is necessary to arrange a good range hood in the kitchen, turn it on whenever cooking, and pay attention to indoor ventilation.

04 Air Quality

The air quality is getting worse and worse, and the quality of air directly affects the health of the public. In October 2013, the International Agency for Research on Cancer under the WHO upgraded atmospheric particulate matter (represented by PM10 and PM2.5) to a Class I carcinogen.

According to a survey, the lung cancer mortality rate has increased by 456% in the past 30 years, which is closely related to the worsening of environmental pollution. The risk of lung cancer in cities with severe air pollution for a long time is 10-15% higher than in cities with relatively clean air. Haze increases the risk of cancer more than smoking, and also increases the incidence of chronic cough, asthma and bronchitis. [5] Therefore, if we want to keep our residents healthy, it is urgent to improve air quality.

05 Dietary factors

Although most people now pay more attention to healthy eating, some people have special eating habits, such as liking to eat pickled foods and animal offal. Studies have shown that eating pickled foods and animal offal frequently are risk factors for lung cancer in women.

From the perspective of dietary health, it is recommended that you eat less pickled foods, as these foods generally have a high sodium content. A high-salt diet can also increase the risk of hypertension, osteoporosis, and gastric cancer. According to the "Report on the Nutrition and Chronic Disease Status of Chinese Residents (2020)", although the daily salt intake of Chinese residents has dropped by 1.2 grams from 9.3 grams in 2015, it still exceeds the "Dietary Guidelines for Chinese Residents" recommended daily intake of less than 6 grams, and is still in a state of needing salt control.

As for animal offal, although eating it properly is good for health and can supplement mineral iron, vitamin B and other nutrients, it cannot be eaten every day. It is recommended to eat it 2 to 3 times a month, 25 grams each time, for example, half an egg size of pork liver is enough.

06 Genetic factors

Lung cancer is also affected by genetic factors, especially female lung cancer has a familial clustering. For non-smoking women, if their parents have a history of lung cancer, then the risk of lung cancer will be higher.

Therefore, it is not only smoking that can induce lung cancer. The above factors are harmful to lung health. In terms of preventing lung cancer, female friends should not only quit smoking, but also try to persuade their families to quit smoking and stay away from secondhand smoke. Cooking must turn on the range hood, eat less pickled foods and animal offal, eat more fresh fruits and vegetables, and insist on exercising to enhance immunity. Finally, isn’t it also good to take turns cooking?

Author | Xue Qingxin, member of Chinese Nutrition Society, registered dietitian, health manager, public nutritionist

Review | Li Nannan Director of Hunan Science Writers Association Deputy Director of Research and Publicity Department of Hunan Science and Technology Association Second-level Researcher Chinese Science Expert (Medical Field)

Editor | Ding Zong

References:

[1] Yang Jie, Yuan Zhenli, Jiang Lina, et al. The mechanism of smoking leading to lung cancer and the current status of vitamin E intervention research [J]. Journal of the Academy of Military Medical Sciences, 2005, 29(4)

:396-398.DOI:10.3969/j.issn.1674-9960.2005.04.027.

[2] Li Bo, Wang Anhui. Research progress on risk factors for lung cancer in women[J]. Medical Review, 2019, 25(18): 3611-3616,

3621.DOI:10.3969/j.issn.1006-2084.2019.18.015.

[3] Li Xu, Li Xiaodan. Harm of restaurant fumes to human health[J]. Energy Conservation and Environmental Protection, 2019, (2): 28-29.

[4] Dong Yang. Impact of China’s air quality on public health: based on a comparison with the G20 countries as a whole [J]. Population and Economy, 2018, (2)

:57-68.DOI:10.3969/j.issn.1000-4149.2018.02.006.

[5]. Chai Jing, Peng Cao. Causes of haze formation and its impact on human health[J]. World Latest Medical Information Abstracts, 2017.

This article was first published on Science Refutes Rumors