Peanut oil, soybean oil, olive oil... Beyond flavor differences, what else sets these cooking oils apart?
Over 99% of cooking oils consist of fats, with variations primarily in fatty acid composition. Fatty acids are categorized as saturated or unsaturated, with unsaturated fats further divided into monounsaturated and polyunsaturated types.Nutritionally speaking, oils higher in unsaturated fatty acids are generally healthier. Monounsaturated fats help lower LDL cholesterol ("bad" cholesterol) and raise HDL cholesterol ("good" cholesterol), thereby preventing cardiovascular disease. Polyunsaturated fats also regulate cholesterol levels, reduce blood lipids, improve circulation, and inhibit blood clot formation.
Research indicates that only when all types of fatty acids are balanced can they promote health. It is recommended that adults maintain a 1:1:1 ratio of saturated, monounsaturated, and polyunsaturated fatty acids in their diet. However, this ratio refers to the entire dietary structure, encompassing both fatty acids in cooking oils and those in animal-based foods like meat, eggs, and dairy(predominantly saturated fatty acids).
The common advice to rotate cooking oils primarily addresses this fatty acid balance. If oils share similar fatty acid profiles, switching between them yields minimal benefit. For instance, soybean oil, corn oil, and sunflower oil are comparable; tea seed oil and olive oil are similar.When substituting oils, it's advisable to choose varieties with distinct fatty acid profiles, such as swapping sunflower oil for peanut oil. Additionally, due to differing fatty acid compositions, oils exhibit varying heat tolerance, suitability for specific cooking methods, and unique advantages and disadvantages. A chart can provide a clear overview of these characteristics.