In February 2020, the International Agency for Research on Cancer (IARC), part of the World Health Organization, released the latest edition of the World Cancer Report.
The report shows that in 2018, about 9.6 million people died from cancer worldwide.
As the most populous country in the world, the number of new cancer cases in China exceeds 23% of the world. Among them, liver cancer, esophageal cancer and stomach cancer account for 1/2 of the world's new cases, and lung cancer new cases account for 1/3 of the world. Cancer deaths in China account for about 30% of the world's total.
In 2019, a study published in the top medical journal The Lancet showed that lung and liver cancer ranked 4th and 7th among the top 10 causes of death in Chinese mouths," respectively [2].
At the same time, the incidence of other cancers such as breast cancer, stomach cancer, colorectal cancer and so on is also increasing year by year.
More importantly, compared with cardiovascular and cerebrovascular diseases, cancer has a greater physical and psychological impact on patients, and often has a shorter survival time. On the one hand, many people "talk about cancer discoloration", on the other hand, it also makes everyone pay more and more attention to the prevention of cancer.
Every year from April 15 to April 21 is the National Cancer Prevention and Control Publicity Week, and this year's theme is "On the Road to Anti-Cancer, You and I Are One Heart".
Today, let's talk about the issues that many people care about: the family genetic problem of cancer, who are at high risk, and how to prevent cancer from the aspects of life and diet.
Cancer families and cancer counties, what the hell is going on?
We often hear that in a small place or family, the proportion of people who get cancer is significantly higher than that of the general population (such as "cancer villages" and "cancer counties"), and even often hear about cases where "several generations of a family have cancer", or "couples have cancer at the same time".
In medicine, this phenomenon is called "crowd aggregation of tumors." And these families or groups of people are also considered to be at high risk of cancer.
However, this situation can often be divided into two categories and need to be treated differently:
1. There is a clear family history of genetic tumor diseases
Some families carry dominantly inherited genetic mutations that significantly increase the risk of cancer among family members.
A typical case is the family of American movie star Angelina Jolie, whose family members carry mutations in the BRCA gene, and women who carry this genetic abnormality are significantly more likely to develop ovarian and breast cancer than the general population.
(Source: BBC)
Angelina Jolie's mother and aunt both died of this type of disease.
In order not to "repeat the mistakes of the past", Julie underwent a preventive resection of both breasts and bilateral ovaries, preventing the recurrence of this tragedy in advance.
It should be noted that tumors with clear hereditary properties are still a minority, generally two or three generations of immediate family members have multiple people with cancer, so it is necessary to suspect whether they carry "cancer genes". For example, BRAC-related breast and ovarian cancer, Lynch syndrome-related colorectal cancer, etc.
At present, many domestic hospitals or genetic testing companies provide genetic testing and genetic counseling services, if you suspect that your family has problems in this regard, you can consider testing to determine whether there is a cause, and then under the advice and guidance of doctors, carry out corresponding interventions.
2. Due to common bad eating habits or environmental factors, the cancer rate of a population in a certain area increases
In some areas with high incidence of cancer in China, such as Qidong in Jiangsu and Linxian county in Henan, there is no clear "genetic gene" that causes a high incidence of cancer, but it is related to local environmental factors, economic conditions and eating habits.
For example, Linxian County, Henan Province, has become a high incidence of esophageal cancer because locals often eat pickled, moldy, hot and high-salt foods;
In the southeast coastal areas such as Qidong, Jiangsu Province, it is because of the high rate of hepatitis B infection itself, coupled with the high degree of aflatoxin pollution in rations, and the long-term use of ditch water as drinking water, resulting in a high incidence of liver cancer.
Specific to a family, diet and living habits tend to be consistent. For example, they all love to eat certain foods, like hot foods, eat salty foods for a long time, lack certain substances in their diet, burn bituminous coal for cooking for a long time, or smoke and alcohol ,etc. (smoking and inhaling second-hand smoke are risk factors for lung cancer).
These can all lead to cancer in couples or multiple people in the family.
However, as long as bad eating habits or environmental factors are corrected in time, the risk of cancer can usually be reduced, and there is no need to panic too much about this phenomenon.
To prevent cancer, what should I pay attention to in terms of diet?
Cancer is a chronic disease, the tumor gradually grows from a single cell to a lump visible to the naked eye, it takes several years or even more than a decade, cancer and our daily lifestyle, eating habits, mood are closely related.
So in addition to the inevitable genetic factors, what can we do in life to reduce the risk of cancer?
1. Eat less or no of these 6 foods!
We often say that the disease comes from the mouth, and cancer is no exception.
Numerous studies have proven that poor eating habits are strongly associated with the occurrence of multiple cancers.
Among them, the most authoritative reference is the classification of carcinogens released by the International Center for Research on Cancer, which is divided into 5 categories according to the degree of carcinogen.
Class 1 carcinogens: sufficient evidence of carcinogenicity in humans, containing a total of 120 substances;
Class 2A carcinogens: limited evidence of carcinogenicity in humans, but sufficient evidence of carcinogenicity in laboratory animals, containing a total of 83 substances;
Class 2B carcinogens: limited evidence of carcinogenicity in humans and insufficient evidence of carcinogenicity in laboratory animals; or insufficient evidence of carcinogenicity in humans, but sufficient evidence of carcinogenicity in laboratory animals. Contains a total of 314 substances;
Class 3 carcinogens: can not be classified for human carcinogenicity, insufficient evidence, and insufficient or limited evidence for experimental animal carcinogenicity.
Class 4 Carcinogens: May not be carcinogenic to humans.
Read more: 120 carcinogens identified by the International Agency for Research on Cancer (IARC) (Category 1)
Among them, some substances are not uncommon in daily life and even on our tables, such as aflatoxin, betel nut, alcoholic beverages, benzopyrene, Chinese salted fish, etc., which belong to Class 1 carcinogens; nitrosamines, red meat, etc. belong to Class 2A carcinogens.
Many of the foods we usually eat, such as cured meat or pickles, fried foods, contain nitrosamines and benzopyrene.
In particular, Chinese-style salted fish, which is salted and then dried, has a dehydration step in the production process, and nitroso compounds, such as nitrosodimethylamine, are generated in the process, which has clear carcinogenicity.
In addition, some poor eating habits, such as eating moldy and spoiled meals and alcohol abuse, can cause us to overexposure in carcinogens such as aflatoxin and alcohol, resulting in a significant increase in the incidence of liver cancer.
In recent years, the harm of betel nut has also attracted attention.
Betel nut is a popular snack in the southern region of China, according to statistics, the annual sales of betel nut has exceeded 50 billion! However, the consumption of betel nut is closely related to the occurrence of oral cancer, and more than 60% of oral cancers are related to the consumption of betel nut. Hunan is the largest province in China that consumes betel nut, and the prevalence of oral cancer in Hunan province is more than 20 times higher than the national average[3]!
From these, it can be seen that keeping your mouth shut, not eating or eating as little as possible these foods with clear carcinogenic effects have a very important role in preventing the occurrence of tumors.
2. Selenium supplementation cannot prevent cancer and fight cancer
Many health care products advertise that "selenium has antioxidant properties" and "selenium supplementation can prevent cancer", but in fact, the human body only needs a very small amount of selenium.
Most studies have shown that selenium supplementation has no practical clinical effect on "reducing the risk of prostate cancer."
For the prevention of colorectal cancer or lung cancer, selenium supplementation also has no effect.
It is important to note that excessive selenium intake may increase the risk of non-melanoma skin cancer!
In addition, a study by the National Cancer Institute (NCI) showed that taking selenium supplements nearly doubled the risk of prostate cancer in men who already had high concentrations of selenium in their bodies [4].
3, these 3 kinds of food can be eaten more
Although there are no absolute "anti-cancer foods" or "anti-cancer nutrients", the combination of certain natural foods has certain benefits for preventing certain cancers.
Colorectal cancer is highly associated with eating habits. The latest research shows that in 195 countries and regions around the world, the three major risk factors for colorectal cancer are:
Diets are low in calcium, alcohol consumption, and eating too little dairy products. At the same time, eating too little dietary fiber is also an important reason.
Therefore, drinking more milk, eating more fresh vegetables, supplementing the calcium, dairy products and dietary fiber in the diet, and drinking less alcohol are important ways to prevent colorectal cancer.
Another recent study of nearly 1.5 million people showed that dietary fiber and yogurt reduced lung cancer risk, with the highest intake of dietary fiber and yogurt, the lowest 17% and 19% lower risk of lung cancer, respectively, and the 33% lower risk of lung cancer in those with the highest intake of both dietary fiber and yogurt [6].
This suggests that dietary fiber and yogurt intake may be somewhat helpful in preventing lung cancer [6].
However, we must pay attention to the nutrients in fresh vegetables, fruits and natural foods mentioned here. Eating health supplements and supplements such as multivitamins and calcium tablets alone cannot be replaced. Only a well-rounded, varied diet is the only way to maintain health.
4, these bad living habits, to change!
In addition to diet, there are many bad lifestyle habits that are related to cancer, such as smoking, lack of physical activity, hepatitis B caused by not vaccinating in time, HPV infection, etc.
If these unhealthy living habits can be changed, the number of cancer deaths in China can be reduced by at least 30 to 40% [7]!
If you smoke and drink, even if you eat more fresh vegetables and fruits, and insist on exercising every day, how much can you remedy it? It's just psychological comfort.
In addition, obesity is also associated with an increased risk of breast, colorectal, thyroid, pancreatic cancer and other cancers. Therefore, for obese people, weight loss is not only for the sake of good looks and prevention of cardiovascular disease, but also to prevent cancer!
Don't hurry up yet!
bibliography
[1] Edited by Wild CP, Weiderpass E, Stewart BW. World Cancer Report: Cancer Research for Cancer Prevention. IARC. http://publications.iarc.fr/586
[2] Zhou M, Wang H, Zeng X, et al. Mortality, morbidity, and risk factors in China and its provinces, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet. 2019. 394(10204): 1145-1158.
Yang Bo, Fu Mengfan. Research progress on the prevalence and effects of chewing betel nut in parts of Asia. Journal of Clinical Stomatology. 2019. 35(1): 58-62.
[4] https://www.cancer.gov/types/prostate/research/select-trial-results-qa#5
[5] The global, regional, and national burden of colorectal cancer and its attributable risk factors in 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet Gastroenterol Hepatol. 2019 .
[6] Yang JJ, Yu D, Xiang YB, et al. Association of Dietary Fiber and Yogurt Consumption With Lung Cancer Risk: A Pooled Analysis. JAMA Oncol. 2019 .
[7] Chen W, Xia C, Zheng R, et al. Disparities by province, age, and sex in site-specific cancer burden attributable to 23 potentially modifiable risk factors in China: a comparative risk assessment[J]. The Lancet Global Health, 2019, 7(2): e257-e269.
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