Oil is a daily necessity. What kind of oil is edible, and which is healthier? I. The Nutrition of Oil
Each type of oil contains many fatty acids, of which linoleic acid, linolenic acid, and arachidonic acid cannot be synthesized by the human body and must be obtained from food. Therefore, these three fatty acids are also known as "essential fatty acids." A deficiency of linoleic acid in children can lead to dry skin, thickened scales, and slow growth and development. Arachidonic acid is a precursor for the synthesis of prostaglandins in the human body. A deficiency of linolenic acid can cause an increase in cholesterol levels in the blood. Some oil advertisements on the market claim that the common benefit of vegetable oils—softening blood vessels and inhibiting atherosclerosis—is a unique feature of certain brands, which is inappropriate and misleading to consumers to some extent.
II. Eating Oil or Fat
Fats are solid at room temperature, while oils are liquid. Both oils and fats are triglycerides. Typically, animal fats like lard are called fats, while vegetable oils like peanut oil, sunflower oil, and soybean oil are called oils. It is recommended to control the intake of animal fats and consume more vegetable oils.
III. Eating Pressed Oil or Extracted Oil
Factories use two methods to produce oil: mechanical pressing and solvent extraction. Therefore, oil is divided into pressed oil and extracted oil. As long as both pressed and extracted oils are of good quality, they are edible.
IV. Eating Refined Oil or Crude Oil
Oil obtained through either pressing or extraction is considered crude oil. Crude oil is a mixture that contains hundreds of impurities besides oil, such as phospholipids, aflatoxins, pesticides, and residual solvents. After refining, harmful substances like aflatoxins, pesticides, and gossypol are removed from the oil. Therefore, the author recommends consuming refined oil and not crude oil.
V. Eating Peanut Oil or Blended Oil
Blended oil is a mixture of several oils in specific proportions, aimed at improving the fatty acid composition and taste. Since people's diets are complex, containing fats from foods like fish, meat, eggs, dairy, vegetables, grains, and fruits, each blended oil can only indicate the proportion of fatty acids it contains. It is impossible to calculate the content of each fatty acid in a person's every meal. Therefore, it is hard to say that the nutritional value and taste of blended oil are better than that of single-species oil.