Cancer has now become the leading cause of death for both male and female residents. Statistics from 2007 show that among urban residents who died that year, 28.53% of deaths were caused by cancer. Data indicates that although the effectiveness of cancer treatment has improved, the 5-year survival rates for some major cancers have not shown significant improvement over the past 20 years.
The development of cancer is closely related to diet. Studies have shown that 30% of cancer deaths are caused by improper diet.
Excessive animal fat (mainly saturated fat) in the diet, too few vegetables and fruits, unscientific cooking methods, unreasonable eating habits, and excessive consumption of certain foods are the main carcinogenic factors. Diet is mainly associated with the occurrence of colon cancer, rectal cancer, breast cancer, prostate cancer, stomach cancer, nasopharyngeal cancer, esophageal cancer, and lung cancer.
Common pesticides include organophosphates, organochlorines, and carbamate insecticides. Organochlorine pesticides mainly include DDT and HCH, whose carcinogenicity is relatively certain, and it has been confirmed that they can accumulate in the human body. Therefore, their use has been banned in China and most other countries.
However, surveys show that in 2000, the daily dietary intake of DDT for Chinese residents was very small, but the intake of HCH was 3.11ug, which had actually increased compared to 1990, mainly from the pollution of aquatic products by lindane.
Because the currently widely used organophosphate pesticides remain in food and the environment for a significantly shorter time than organochlorines, they have less relationship with human tumors.
2. Polycyclic aromatic hydrocarbons (PAHs)
The generation of polycyclic aromatic hydrocarbons is mainly related to the incomplete combustion of organic matter. To date, more than 400 types of PAHs have been discovered, of which about 20 are carcinogenic to experimental animals, and benzo(a)pyrene is the most important and common one. Benzo(a)pyrene in food mainly comes from grilled foods, food processing and packaging pollution, etc.
3. Harmful metals
The three metal elements, lead, arsenic, and cadmium, may have carcinogenic effects on the human body. They mainly come from air pollution, water pollution, soil pollution, and food processing contamination, and are the most difficult type of environmental pollutants to control in food. Generally, these are found in fish, seafood, aquatic products, high-fat meats, some vegetables and grains contaminated by factory wastewater, waste gas, and waste residue.
4. Environmental estrogens
Environmental estrogens mainly include substances such as diethylstilbestrol, polychlorinated biphenyls (PCBs), and dioxins. Diethylstilbestrol is one of the growth-promoting hormones commonly used in animal feed and is also a sex hormone.
Both PCBs and dioxins are the most common environmental pollutants and are mainly concentrated (bioaccumulated) in the fat tissues of animals. Therefore, one should eat less high-fat meats, such as fatty meat, pork belly, lean and fatty meat, ribs, high-fat steaks, fatty duck, fatty goose, etc.
5. Vinyl chloride
In daily life, vinyl chloride mainly comes from polyvinyl chloride (PVC) plastic bags used for packaging food. PVC is somewhat toxic because it contains unreacted monomer—vinyl chloride—and additives. It should not be used for food packaging, and the state also has regulations to limit its use, but it is still widely used in farmers' markets to package food.
In comparison, polyethylene is safe and non-toxic and can be used for food packaging. Currently, larger supermarkets use this type of plastic for food packaging. Its characteristics are a waxy luster on the surface, a smooth and slightly hard feel to the touch, and it makes a sound when rubbed forcefully.
6. Nitrates and nitrites
As a coloring agent, nitrates and nitrites are often added to meat products in the form of mixed salts, such as various types of ham sausages and luncheon meat.
Nitrites can be used to synthesize N-nitroso compounds in food or in the stomach. Most (80%) of N-nitroso compounds, such as nitrosamines, are relatively clear carcinogens.
In addition to meat products, pickled vegetables (such as sauerkraut) and stale vegetables are also important sources of nitrites.
Furthermore, some processed foods, such as smoked fish, cured meat, soy sauce, beer, and fried bacon, contain higher levels of N-nitroso compounds.
Studies have found that consuming vitamin C, E, and fresh vegetables and fruits, garlic, onions, tea, kiwi juice, lemon juice, etc., can block the synthesis of the carcinogenic N-nitroso compounds.
7. Artificial synthetic colors
Most artificial synthetic colors are synthesized from coal tar or aromatic hydrocarbon compounds such as benzene, toluene, and naphthalene. Most are harmful, and countries strictly limit their use.
The synthetic colors currently permitted for use in China mainly include amaranth, lemon yellow, and indigo blue. Given that synthetic colors may have carcinogenic effects on the human body, their use should be minimized or avoided.
8. Sodium formaldehyde sulfoxylate (Rongshida or "White Powder")
The chemical name of sodium formaldehyde sulfoxylate is formaldehyde hydrogen sulfite sodium. It is an industrial bleaching agent and not a permitted food additive. However, unscrupulous individuals add it to processed foods such as yuba (bean curd sticks) and rice noodles.
Sodium formaldehyde sulfoxylate has been listed by the International Agency for Research on Cancer (IARC) as a possible human carcinogen.
9. Sudan red
Sudan red is a chemical dye and is not a permitted food additive. However, many merchants use it in foods that require a red color, such as red-hearted duck eggs, chili sauce, seasonings, pickles, and spicy instant noodles.
After the "red-hearted duck egg" incident was exposed in 2005, the use of Sudan red in food was banned. Sudan red is also a possible human carcinogen identified by IARC.
10. Malachite green
Malachite green is a green crystalline substance with a metallic luster, which is easily soluble in water and forms a blue-green solution. It has a considerable bactericidal effect. Some unscrupulous traders abuse malachite green to disinfect fish ponds, trucks, or containers used for transporting fish to prevent fungal infections caused by scale shedding. This once led to the well-known "dover sole" drug residue incident.
15. High-protein diet
Some population surveys and animal experiments have shown that excessive intake of animal protein can significantly increase the risk of breast cancer, colon cancer, rectal cancer, pancreatic cancer, endometrial cancer, and prostate cancer.
However, only "red meat" (beef, pork, lamb and their products) has a significant effect, while "white meat" such as fish, chicken, and duck does not have this risk. Therefore, the intake of red meat should be limited. Surveys indicate that processed meat products have a stronger effect in increasing cancer risk than raw meat.
16. High-fat diet
It is generally believed that fat, especially saturated fat from meat, is a major dietary risk factor for cancer and is closely related to breast cancer, colon cancer, etc. Controlling fat intake, especially from red meat, plays an important role in reducing cancer risk.
17. Alcohol consumption
Long-term alcohol consumption may be an important cause of esophageal and gastric cardia cancer.
It is generally believed that alcohol consumption is closely related to the occurrence of tumors in eight sites: tongue cancer, oral cancer, pharyngeal cancer, esophageal cancer, stomach cancer, pancreatic cancer, lung cancer, and kidney cancer.
Some studies have pointed out that there is a synergistic carcinogenic effect between alcohol consumption and smoking.
18. Preference for very hot food
Some poor eating habits, such as frequently eating very hot (scalding) food and eating too quickly, can damage the esophageal mucosa, cause chronic inflammation, and increase the risk of esophageal and stomach cancer.