"Oh, Lao Zhang, your fried snacks are so delicious!" Aunt Li was attracted to the door of her neighbor's house by a tempting aroma. I saw Lao Zhang standing in his small courtyard, skillfully turning a steaming iron pot.
"Of course, I use home-squeezed oil, fried thoroughly, and the taste is authentic. The old man didn't raise his head, and responded proudly. On holidays, Lao Zhang always likes to squeeze oil and fry food to entertain relatives and friends.
"Home-squeezed oil......? Don't it be produced by a small workshop, right?" Although Aunt Li praised it, she couldn't help but put a question mark in her heart. Just last night, she saw an article on her phone about cooking oil.
The article mentions that some oil products may be the "invisible promoters" of liver cancer, thinking of Lao Zhang's old oil pot that never seems to go out, and his proud self-squeezing oil, Aunt Li can't help but sweat for the health of Lao Zhang's family.
Aunt Li knew that although Lao Zhang was sincere, he was not proficient in food safety knowledge. This discussion about the choice of edible oil quietly kicked off in the neighborhood.
01. The role and nutritional value of edible oil
Energy source: Cooking oil is an efficient fuel for the body to obtain energy. Moderate intake of edible oil helps to maintain normal body temperature, support physical activity, and provide necessary energy supplements, especially in high physical exertion or special physiological stages.
Essential fatty acids: Cooking oils are an important dietary source of essential fatty acids – linoleic acid and α-linolenic acid. These fatty acids, which the body cannot synthesize on its own, are essential for maintaining good health.
Fat-soluble vitamin carriers: Edible oil is an ideal carrier for fat-soluble vitamins, which are essential for vision, skin health, immune function and fetal development. It is found in the form of retinol converted from carotene, which is commonly found in palm oil, olive oil, etc.
Flavor carriers: such as olive oil, with a strong olive fruit aroma, suitable for cold dressing, low-heat cooking, adding a natural and fresh taste to the dish. For example, peanut oil and walnut oil contain the unique mellow aroma of nuts, which is suitable for stir-frying, baking, and increasing the rich taste of food.
Cooking medium: The high heat capacity and good thermal conductivity of the grease allow the food to be heated quickly and evenly, reducing the cooking time and preserving the original flavor of the ingredients. Apply or spray on the surface of the pot to form a lubricating film to prevent food from coming into direct contact with the bottom of the pot and avoid scorching and sticking.
02. These 3 oils can be called the "accelerator" of liver cancer
Oil used for repeated frying: Repeated high-temperature heating promotes the oxidation of fatty acids in edible oil to produce oxidized lipids, aldehydes, ketones and other harmful substances, which can directly damage liver cells and induce inflammatory reactions, and long-term accumulation may increase the risk of liver cancer.
During the frying process, carcinogenic polycyclic aromatic hydrocarbons (PAHs) are produced by interacting with high-temperature oils in the food and in high-temperature oils. These substances can enter the body with food and cause damage to liver cells when detoxified by the liver.
Partial unsaturated fatty acids will be isomerized at high temperatures for a long time to form trans fatty acids. Some studies have suggested that trans fatty acids may be involved in the development of liver tumors.
Oil that has been in place for more than a year after opening: After opening, the edible oil gradually oxidizes under the action of oxygen, forming highly reactive free radicals. These free radicals can attack biomolecules such as cell membranes and DNA in the liver and other organs, causing cell damage, inflammation and gene mutations, increasing the risk of liver cancer.
Oxidative oil contains fatty acid oxidation products such as lipid peroxide, which not only reduces the nutritional value of oils, but also triggers oxidative stress in the body, causing chronic damage to organs such as the liver.
The fat-soluble vitamins originally contained in edible oil stored for a long time will gradually degrade, lose their antioxidant protection effect, and further intensify the oxidation process of oils and fats.
Oil extracted from small workshops: If the raw materials for oil extraction in small workshops are not properly stored, it is easy to breed Aspergillus flavus and produce aflatoxin, a strong carcinogen. Aflatoxins are extremely toxic to the liver, and long-term ingestion of small amounts can lead to hepatocellular damage, which is an important factor in inducing liver cancer.
The oil extraction equipment of the small workshop is poor, which may not be able to effectively remove impurities, pesticide residues and other harmful substances in the raw materials, resulting in the quality of the oil is not up to standard, and long-term consumption poses a potential threat to the liver.
A small number of illegal small workshops may have adulteration and illegal additions, such as the use of inferior raw materials, excessive addition of antioxidants, and the use of industrial oils, which may pose a serious harm to the liver health of consumers.
03. The correct way to eat edible oil
Correct use: Avoid repeated high-temperature frying, try to choose disposable frying or special frying oil, and replace it in time. The leftover oil after frying should not be used for other cooking, especially high-temperature stir-frying.
Pay attention to the expiration date of the oil: When buying edible oil, pay attention to the production date and expiration date to ensure that it is used within one year after opening. After opening, it should be properly stored, sealed, protected from light, and stored at low temperature to slow down the oxidation rate of grease.
Preferred formal channel products: When purchasing edible oil, priority is given to large-scale enterprise products with well-known brands, complete production information, and national quality certification to ensure oil quality and safety. Resolutely resist the extraction of oil from unlicensed small workshops and bulk oil from unknown sources.
Healthy cooking habits: Reduce high-temperature frying, and use more low-fat cooking methods such as steaming, boiling, stewing, roasting, and cold dressing, which can not only retain the nutrition of ingredients, but also reduce harmful substances produced by high temperatures.
Healthy eating habits are the first line of defense against various diseases, and scientific understanding and careful selection of edible oil are the key to protecting liver health.
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