They are polyunsaturated oils obtained from seeds such as cotton, sunflower, soy, corn, linseed, etc. Vegetable seed oils have been considered a good option because they are cheap and do not change the taste of food. However, they contain short-chain fatty acids, and they separate more easily when heated, releasing more free radicals.
Dangers of vegetable seed oils
Production of aldehydes: When the oil is heated to high temperatures for a long time, toxic substances called aldehydes are formed. These substances have been linked to an increased risk of cancer and other diseases (*).
The heating of these oils triggers hydrolysis, oxidation, and polymerization processes. It rapidly degrades their properties and generates problematic compounds (*).
The amount of aldehydes is related to the type of oil, the temperature, and the length of the cooking time.
Reheating the oil also increases the formation of aldehydes, it is associated with higher levels of vascular inflammation, blood pressure and free radicals.
They are rich in polyunsaturated fatty acids, and Omega 6 (linoleic acid) is the main fatty acid present in these oils: Omega 3 and 6 fatty acids are a type of essential fat. Therefore, our body cannot produce them and has to acquire them through the diet. Our body requires a balanced ratio for the two to function adequately. Therefore, an excess of Omega 6 can cause inflammation, which increases the chances of suffering from numerous diseases such as allergies, arthritis, lupus, cancer, psoriasis, metabolic syndrome, etc (*; *; *; *; *). Given the high consumption of this type of oil in the West, most of the inhabitants have 25 times more Omega 6 than 3, the amount of linoleic acid we store has increased (*).
Omega 6 accumulates in LDL particles (those that carry cholesterol), contributing to its oxidation. Studies show that the higher amounts of Omega 6 from vegetable oils, the greater the risk of coronary heart disease (*;*).
What is the best option?
Extra virgin olive oil is more stable (It has a lot of omega 9, which makes it more resistant to heat). However, there are variations according to the type of olive and method of production. Coconut oil (and especially the cold-pressed virgin) is also a good option.
Vegetable does not always mean healthy.
Look at the ingredient list and choose the best for your health and well-being.