Vegetable oils, some highly valued in cooking, are rich in polyunsaturated fatty acids and can contribute to cardiovascular health if they are well chosen and used sparingly.
Fats are an essential type of nutrient in our diet and are found in many natural foods. But human intelligence has also made it possible to extract them and isolate them from food to use them as an ingredient in many different ways. The idea is not new: the possibility of extracting the liquid oil from fruits and oilseeds dates back at least four thousand years.
The supply of vegetable oils is wide and keeps increasing. The most used in food are sunflower, soybean, rapeseed, corn, peanut and safflower. But more and more are known oils that constitute real delicacies: grape seeds, sesame, borage, and argan, pumpkin seeds … All these oils are rich in polyunsaturated fatty acids (PUFA).
1. WHAT IS THE BEST VEGETABLE OIL?
In our environment, the vegetable oil par excellence and the star of the Mediterranean diet is olive oil. One of the main reasons is to be found in oleic acid, the monounsaturated fatty acid that has by far the highest proportion and is considered a cardiovascular protection factor.
2. HOW MUCH POLYUNSATURATED FATTY ACIDS SHOULD WE CONSUME?
In general, it is recommended that polyunsaturated fatty acids (PUFAs) contribute 4 to 10% of the total daily energy. On a 2,000 calorie diet, this amounts to 9 to 22 g per day. Of that amount, the recommendation for omega-6 (linoleic acid) is 4 to 8%; a consumption of about 15 g per day has recently been proposed. For omega-3s (alpha-linolenic acid), the recommendation is 0.5-1%, that is, between 1 and 2 g in a diet with those calories.
3. IS SUNFLOWER OIL ADVISABLE?
In Spain it is one of the most consumed oils. It is very rich in linoleic acid, so much so that only two tablespoons (20 g) already provide about 12 g, so the recommended amounts can easily be exceeded. On the other hand, it is low in oleic acid and very low in omega-3.
4. HOW MUCH OIL CAN BE TAKEN PER DAY?
Vegetable oils are at the top of the nutritional pyramid. In practice this translates into the convenience of limiting its consumption to small daily amounts. As a general rule, a consumption of between 30 and 50 g per day is recommended, corresponding to three or five tablespoons, respectively.
5. WHY SHOULD THE CONSUMPTION OF OILS BE MODERATED?
Largely due to its high caloric content. An excessive presence in the diet would limit the space allocated to carbohydrates, the body’s main source of energy. On the other hand, you could reduce your intake of the recommended daily amounts of water-soluble vitamins and minerals, which are the majority.
6. ARE SUNFLOWER OR CORN LIGHTER?
No. All commonly consumed oils contain practically 100% fat. What distinguishes one oil from another is the quality of its fats and not the quantity; its energy contribution is the same. A higher degree of unsaturation results in a more fluid appearance, but this does not mean fewer calories.
7. DOES ANY VEGETABLE OIL PROVIDE OMEGA-3S?
The main omega-3 present in oils is linolenic acid, an essential fatty acid, but the amounts vary widely. Among the richest oils are those of flax, walnuts, rapeseed and soybeans. On the contrary, the amounts in some of the most consumed, such as sunflower and corn, are insignificant.
8. WHAT IS THE MOST ADVISABLE OIL FOR COOKING?
The most advisable fat for cooking is olive oil, as it withstands high temperatures better. The other oils, having a higher percentage of polyunsaturated fats, are more sensitive to heat, so it is preferable to reserve their use for cold preparations, such as dressings, sauces or certain types of pastries.
9. WHAT DOES “VEGETABLE OIL” MEAN ON A LABEL?
When a product contains a prestigious oil, such as olive, it usually indicates it on the label. If you put “vegetable oil”, it can contain any oil or mixture of oils: they are often very refined or well saturated, such as palm or coconut; they can also be hydrogenated.
10. WHAT OTHER ASPECTS SHOULD BE CONSIDERED?
The origin of the raw material, as it is different whether it is biological or transgenic; and the method of obtaining it, since priority should be given to oils subjected to fewer manipulations. In addition, it must be remembered that all oils are sensitive to light and heat, and that they must be kept in tightly closed containers.