Excessive consumption of pickled vegetables can easily stimulate excessive gastric acid secretion, leading to hyperchlorhydria, and even peptic ulcers. During the pickling process, pickled vegetables have high acidity. When the oxalic acid they contain enters the gastrointestinal tract, it reacts with the calcium present to form calcium oxalate, which can lead to urinary system stones. In the pickling process, pickled vegetables are easily contaminated by microorganisms, which can reduce them to nitrites. Consuming pickled vegetables with excessive nitrites can cause hemoglobin in the blood to turn into methemoglobin, which loses its oxygen-carrying function, leading to hypoxia and poisoning. Symptoms of poisoning include cyanosis of the skin and lips, headache, dizziness, nausea, vomiting, and palpitations. Severe cases can be fatal. Furthermore, the pickling process can also produce carcinogenic nitroso compounds, which can easily induce cancer, especially in moldy pickled vegetables, whose carcinogenic effect is more pronounced.
Therefore, experts warn: When eating pickled vegetables, be sure to pay attention to the following points: Pay attention to the pickling method. It is inevitable that nitrites will be produced during the pickling process. If the nitrite content in 1 kg of pickled vegetables exceeds 150 mg, it will cause poisoning. To reduce the nitrite content in pickled vegetables, first, add some vitamin C when pickling. For 1 kg of cabbage, add 4 tablets of vitamin C. The main role of adding vitamin C is to block the formation of nitrites. Adding 400 mg of vitamin C or 50 mg of the preservative benzoic acid can block 75% and 98% of nitrite production, respectively. It can also prevent the pickled vegetables from growing mold and reduce sourness and off-flavors. Second, use enough salt and pickle thoroughly. Insufficient salt will not completely inhibit bacteria, causing nitrates in the vegetables to be reduced into harmful nitrites. Third, ensure sufficient pickling time. The nitrite content shows a significant peak during the pickling process. Under normal circumstances, the nitrite content in pickled products is highest between the 4th and 8th days of pickling, starts to decrease on the 9th day, and begins to disappear after 20 days. At this point, it is safe to eat.
Precautions for buying or eating pickled vegetables outside When you don't want to pickle them yourself and go to the market to buy pickled vegetables, first pay attention to selecting high-quality ones. A good, whole pickled vegetable should have pale, translucent stalks and slightly yellowed leaves. After buying pickled vegetables, wash them thoroughly until the rinsing water is cool. Second, when eating pickled vegetables in a restaurant, observe the color. The soup cooked from high-quality pickled vegetables is light yellow, while vegetables that are golden in color are definitely of poor quality, caused by the addition of industrial dyes. Third, it is best to buy pre-pickled vegetables from large supermarkets or stores, and choose products from regular manufacturers. Many small shops sell quick-pickled vegetables, which are rapidly pickled with glacial acetic acid. Some producers also add industrial dyes like "Sunset Yellow" or "Citrus Yellow" to make the pickled vegetables look more appealing. When eating pickled vegetables, it is best to consume them together with fresh vegetables. It is best to eat pickled vegetables together with foods rich in vitamin C, such as fresh vegetables like chili, cauliflower, cilantro, garlic seed, mustard, bitter gourd, and preserved potherb mustard; and fruits like fresh oranges, grapefruits, fresh dates, hawthorn, cherries, kiwis, and strawberries. This is because vitamin C can react with nitrites to prevent the formation of carcinogenic substances. You can also take vitamin C orally before or after a meal.
Do not consume pickled vegetables excessively or for long periods Nitrites are naturally occurring substances in the diet and enter the human body daily with grains, vegetables, fish, meat, eggs, and dairy products. The average content of nitrites in vegetables in nature is about 4 mg/kg; while in various pickled preserved vegetables, the average content is over 7 mg/kg. Although the vast majority of nitrites in the daily diet are excreted in urine as "passers-by," if the body's nitrite content exceeds 200 mg, the situation becomes serious.
In addition, epidemiological surveys have shown that in some regions in China where pickled foods are consumed long-term, the incidence rate of esophageal cancer remains high. One of the main causes is the long-term and large consumption of pickled vegetables. The incidence rate is proportional to the amount and duration of consumption. Therefore, when eating pickled vegetables, moderation is key. Absolutely do not eat pickled vegetables that have spoiled or become moldy. If symptoms such as general fatigue, palpitations, shortness of breath, and abdominal distension appear after eating pickled vegetables, seek medical attention immediately.