With the improvement of living standards, more and more people are paying more and more attention to the topic of health and wellness, especially in terms of diet. However, if you are not careful, healthy food can become carcinogenic, and the effect can be counterproductive!
Tea → hot tea
Tea is a natural health drink for most people, and drinking tea in particular can also reduce the risk of cancer. A 2020 study published in Advances in Nutrition found that drinking tea can really prevent cancer, especially oral cancer. Consuming a variety of teas at the same time has been linked to a reduced risk of many cancers such as stomach cancer, colorectal cancer, biliary tract cancer, liver cancer, etc. ①
However, drinking tea in the wrong way can also cause cancer! Wang Boshi, a dietitian at the Department of Clinical Nutrition at Peking University People's Hospital, said in an article in Health Times in 2019 that drinking tea with too high temperature may burn the esophageal mucosa and increase the risk of esophageal cancer and stomach cancer. ②
Ginger → moldy, rotten ginger
As the saying goes: eat radish in winter and ginger in summer. Eating more ginger in summer has become the choice of many health people. Chen Hong, deputy chief physician of the Department of Traditional Chinese Medicine of Donghu Hospital in Wuhan City, Hubei Province, said in an interview with Yangtze River Daily in 2022 that the curcumin contained in ginger has antioxidant, anti-inflammatory, anticoagulant, lipid-lowering, anti-atherosclerosis, anti-aging, free radical scavenging and other effects. ③
However, if it is moldy and rotten, ginger can become a carcinogen! Li Junxian, the attending physician of the Department of Traditional Chinese Medicine of Sichuan Provincial People's Hospital, said in an article published by Sichuan Famous Doctor in Chengdu Business Daily in 2023 that ginger that has been left for too long is easy to spoil and moldy, resulting in a carcinogenic risk! The "safrole" contained in ginger is a carcinogen and has been included in the World Health Organization's List of Group 2B Carcinogens. Generally, fresh ginger contains only a very small amount of safrole, which will not cause harm to the human body. However, once the ginger becomes moldy and rotten, its safrole content will increase dramatically, and long-term consumption will increase the risk of cancer. ④
Nuts → moldy nuts
Nuts are a very good source of protein, calcium, iron, zinc and vitamin E, and they are also rich in unsaturated fatty acids, which are good for health. According to the Dietary Guidelines for Chinese Residents 2022, moderate intake of nuts is good for health. An average of 50-70 grams per week is recommended.
However, improper storage or prolonged storage can cause rancidity and a hala or bitter taste in the unsaturated fatty acids in nuts.
Moldy nuts, in particular, are prone to aflatoxin, which is a Group 1 carcinogen. If you eat too many moldy nuts at one time or eat them for a long time, it may damage your organs and cause poisoning.
Vegetables → pickled vegetables
Fruits are essential for a healthy diet! Intake of sufficient amounts of fruits can provide the human body with daily essential vitamins, minerals, dietary fiber and other nutrients, which is an important part of a reasonable diet. However, people who are accustomed to eating pickled vegetables should be careful, as pickled vegetables can easily increase the risk of cancer.
In 2023, a team from Zhejiang University School of Medicine published a study on the dangers of pickles in the journal BMC Medicine, pointing out that people who ate pickles four or more days a week had a 13% higher risk of death from digestive tract cancer and a 45% higher risk of death from esophageal cancer. ⑤
Yu Weiming, chief physician of the Department of Gastrointestinal Surgery of Li Huili Hospital of Ningbo Medical Center in Zhejiang Province, also said in an interview with Ningbo Evening News in 2023 that stomach cancer is inseparable from the habit of eating pickled food. Pickled food contains a lot of nitrite, which will irritate the gastric mucosa after long-term consumption, making it dysfunctional, congested, edema, erosion, and increasing the chance of gastric mucosal cancer. ⑥
Seafood→ seafood that is eaten raw
Eating seafood has many benefits for the body, and seafood is very rich in protein and trace elements. In particular, the "Mediterranean diet", which has repeatedly occupied the list of best diets, advocates eating seafood every week.
But it's easy to overlook that seafood is also an intermediate host for many parasites. Eating raw or semi-raw foods containing infectious parasites is susceptible to foodborne parasitic diseases.
Huang Ming, a technician in charge of the laboratory department of Tongji Hospital affiliated to Tongji Medical College of Huazhong University of Science and Technology, pointed out on the hospital's WeChat public account in April 2024 that liver flukes are caused by eating raw or undercooked freshwater fish or shrimp containing Clonorchis sinensis cysts. It is known as the invisible "killer" of the human body, and the clinical manifestations are mainly gastrointestinal symptoms and hepatobiliary symptoms. Liver flukes are a class of carcinogenic organisms recognized by the International Cancer Society and the World Health Organization, and are important triggers of hepatobiliary carcinoma and liver cancer.
Spices in daily life, such as wasabi, vinegar, soy sauce, etc., are basically impossible to kill insects once they are dipped and soaked. So let's cook the fish honestly and eat it. ⑦
Meat → meat after grilling
Meat food is a delicacy and a commonly used food at home, which has a special role in the nutritional needs of human beings. It not only provides an excellent source of protein in terms of quality and quantity to meet the needs of all essential amino acids, but is also a rich source of trace elements such as phosphorus, iron, copper and zinc.
However, if it is not cooked in the right way, it can easily become a carcinogenic food. Xue Qingxin, a member of the Chinese Nutrition Society and a registered dietitian, pointed out in an article published in Popular Science China in 2023 that barbecue is a high-temperature cooking, with a temperature of up to 370 °C, and at such a high temperature, meat will produce heterocyclic amines and polycyclic aromatic hydrocarbons, both of which are carcinogens, and the carcinogen content will gradually increase with the increase of temperature and the extension of time. Fried and grilled foods account for the vast majority of dietary intake of polycyclic aromatic hydrocarbons. ⑧
Cooking oil → oil that has been fried repeatedly
Cooking oil is an indispensable part of the daily diet, it gives food deliciousness, provides people with energy and a variety of nutrients, and is of great significance for health. However, there is a cooking oil that increases the risk of cancer in the body. Xue Qingxin, a registered dietitian, pointed out that the oil used in fried food is "back to the pot oil" if it continues to be cooked at high temperatures repeatedly, and eating such oil regularly is not small for the body.
After high-temperature treatment and repeated "back-to-the-pot" use, oils and fats are easy to produce a variety of carcinogens, such as acrylamide, polycyclic aromatic hydrocarbons, heterocyclic amines, etc. There are some data mentioning that the content of malondialdehyde can be increased to more than 30 times in the return oil that has been used 7 times. Many people may be unfamiliar with malondialdehyde, which is actually a product of rancidity of oils and fats, and has certain toxic side effects. Excessive malondialdehyde intake will not only reduce animal physical performance, damage nerves, and destroy intestinal cell structure, but also have mutagenic and carcinogenic effects. ⑨
Source: Health Times