Recently, a message titled "One Less Fish on the Dining Table—Suancai Fish, Because It's 100% Carcinogenic—Nanjing Doctor Diagnoses 4 Young Gastric Cancer Patients in a Row Who All Love Suancai Fish. Shocking!" was wildly shared on WeChat Moments. The editor truly wants to express indignation: Can we just eat our meals in peace! But, is the harm from "Suancai Fish" really that severe? Today, the editor will uncover the truth with you!
"Suancai Fish is 100% Carcinogenic"—Misinterpretation and Exaggeration
The "Nanjing doctor" mentioned in the WeChat post, Jia Shaochang, Director of the Center for Biotherapy of Cancer at the 81st Hospital of the PLA, stated in a media interview: "This is an embellishment and distortion of our original statement." Jia Shaochang explained that while their department did indeed have four gastric cancer patients who shared a common trait of "liking to eat Suancai Fish," and he had presented this case to the media, when speculating on the causes of gastric cancer, he only suggested that the nitrites in Suancai Fish might increase the risk of cancer. "At most, this is just a contributing factor, not the main cause. The '100% carcinogenic' claim in the WeChat post was something someone else arbitrarily attributed to us."
Jia Shaochang stated that the vast majority of malignant tumors, including gastric cancer, currently have unknown causes. It is only known that they are the result of long-term interactions from multiple factors such as physical, biological, environmental, physical, genetic, psychological, and food chain factors. To determine if a specific food is directly carcinogenic, one must not only consider the intake amount and duration but also rely on extensive epidemiological surveys and evidence-based medicine. As a doctor with 30 years of medical experience, I would never make such an unreliable conclusion as "Suancai Fish causes gastric cancer" based on just four small-sample cases.
Nitrites Carcinogenic? Increased Risk Does Not Equal a Definitive Fact
Strictly speaking, nitrites are a type of toxic substance, not a direct carcinogen. Their median lethal dose is 22mg/kg. For a person weighing 60kg, this would be 1.32g. The recent incident in Guangzhou where a vendor used nitrites to process duck necks and poisoned 8 people was precisely due to the toxicity of nitrites. Nitrite content is very widespread and is a food additive permitted in many countries. It exists in a wide variety of ingredients, with leafy green vegetables being a major source. According to surveys, about 80% of the nitrites in the Chinese diet come from vegetables.
Although nitrites themselves are not carcinogenic, they can easily react with protein decomposition products under acidic conditions to form carcinogenic nitrosamines. The pH level of the stomach is恰好 suitable for the formation of nitrosamines. In cases of insufficient stomach acid, bacteria in the stomach can proliferate and reduce nitrates in food into nitrites, further increasing the risk of gastric cancer. According to the International Agency for Research on Cancer's classification of carcinogens, nitrosamines are classified as "Group 2a," which means "probably carcinogenic to humans." This definition implies "limited evidence of carcinogenicity in humans, but sufficient evidence in animal studies, with no elevated cancer incidence found in human populations consuming the substance compared to non-consuming populations." In other words, while nitrites may have some effect on the human body and excessive intake may increase the risk of gastric cancer, "increased risk" does not mean "definitely carcinogenic."
Staying Away from Nitrites—It's More Than Just Eating Less Suancai Fish!
The main reason Suancai Fish has come under criticism is that its main side dish, pickled vegetables, is a type of pickle that contains a large amount of salt and thus a considerable amount of nitrites during the pickling process. However, nitrites are not far from us; they are all around us. How can you eat well to stay away from them?
1. Stay away from brightly red-colored meat
Nitrites themselves are white crystals, similar to table salt. However, when added to meat, they can bind with the hemoglobin in the meat to form pink nitrosylhemoglobin, giving the cooked meat a desirable pink color. The redder the raw meat, the heavier the browning after cooking. In this era where consumers "judge by appearance," to make meat have a more tender and beautiful color, manufacturers may add large amounts of nitrites to achieve this pink hue and tender texture. Eating too much of this type of meat can be harmful to your health. Cooked chicken should be white or grayish, pork should be grayish or light brown, and originally red beef and mutton should become light brown to brown. If the color is pink, and this pink is consistent from the inside to the outside, then nitrites have definitely been added.
2. Eat less freshly pickled vegetables
Everyone knows that pickled foods are unhealthy, and besides their high salt content, the high levels of nitrites or nitrosamines are the main reasons. Generally, the nitrite content in pickled vegetables drops significantly after 20 days and is considered very safe after a month. Therefore, don't rush to eat freshly pickled sauerkraut, beans, etc. Waiting another month to eat them can effectively reduce the nitrite content. Additionally, adding fresh garlic, fresh ginger, fresh chili, or vitamin C during the pickling process can also reduce nitrite levels.
3. Eat less leftover food from the previous day
The claims that "leftover food is carcinogenic" and "leftover tea is carcinogenic" have become old news online. Due to the long storage time, leftover food can have a lot of bacterial growth, which may produce more nitrites. Leafy green vegetables contain a lot of nitrates and are more likely to form nitrites. It is best to blanch leafy greens in boiling water before cooking, which can cause most of the nitrates to leach into the water. If you buy too much at once and can't finish it, you should blanch it, then seal it in a container and store it in the refrigerator to reduce nitrite formation. Leftovers should be put in the refrigerator immediately and finished the next day.
4. Drink less hot pot broth
Hot pot broth generally becomes saltier the more you cook in it. This is because nitrites from the meat and vegetables leach into the broth during the cooking process, greatly increasing the nitrite content in the broth. When eating hot pot, you should choose broths with less pickled vegetables and seafood. If you really want to drink the broth, pour a bowl at the very beginning before adding any meat or vegetables, and then do not drink it afterward.