When talking about nutrition, “fat” sounds almost like a dirty word. Cardiovascular diseases, being overweight … But we almost forget that fats are essential to the proper functioning of our body. In fact, fat is a family whose members have varying nutritional values, and are more or less good for our health. So should we show privilege to the olive oil over the butter? What are the risks of a diet too high in fat? Where do we find good sources of fat?
In fact, fats are not a simple as what people used to think. They are more complex than they appear. From a chemical point of view, they are classified into eight categories. Among the best known is the fatty acids category which includes omega 3’s. Sterols (such as cholesterol and triglycerides) are the form of storage of fatty acids in the adipose tissue.
Once in the body, it is in the stomach that the digestion of fat is mainly performed. Here, bile salts and pancreatic juices will help to cut the large lipid molecules into smaller fatty acids, making them able to cross the intestinal wall to reach the bloodstream. Much will be stored in adipose tissue. Fats are a very energy source: 1 g of fat produces 9 Kcal, 33 Kj.
In addition to this energetic role, fats are essential to the functioning of the body. They provide heat. Lipids are also cellular messengers. They enter into the composition of the membranes surrounding the cells. But in excess, they can become a health hazard.
To help distinguish between good and bad fats, in summary you have on one side the fats of animal origin, and the other includes fatty acids of vegetable origin.
The first, called saturated fatty acids, are found in red meat, eggs and dairy products. The latter are called unsaturated fatty acids, and most of them are from plant origin. They are mainly found in oils such as canola, olive oil or peanut oil, but also in fish. Some unsaturated fatty acids help to lower bad cholesterol. Those that are part animal fat may encourage the development of cardiovascular disease when they are in excess.
We are constantly told to eat balanced diet, emphasizing fruits and vegetables and limiting our intake of fat. This does not necessarily mean that one should be confined to grated carrots or lettuce. The consumption of fat is essential.
Today, specific recommendations allow consumers to know how much and what type of fat to consume for a balanced diet. The determination of these thresholds depends on a complex work on the assimilation of fats.
In many countries, people consume far more omega 6’s than omega 3’s, because they are found everywhere. Our metabolism is not the same as we consume omega 6’s and omega 3’s; the omega-6 has an inflammatory effect on the cells, while the omega 3 has an anti-inflammatory one.
The interest is to optimize the ratio of omega 6 to omega 3 benefits for both sides (growth and brain development) and to avoid discomfort between the two in the metabolism. The consumer must therefore reduce its intake of omega 6 and increase the intake of omega 3.
Butter or margarine on our toast, oil in our salads, our fries … Fats are essential for our body. Still, we need to know how to use them effectively.
When we cook with butter, margarine or oil, there are some rules to follow to keep the benefits and avoid the production of compound toxins in our bodies.
First criterion: to choose the right oil. According to Professor André Picot, a toxio-chemist based in Paris, France, “We must use the most stable possible oils (groundnut, sunflower) and avoid highly unsaturated oils (olive oil, nuts …).”
Choosing the right oil is a good thing, but we must pay attention to its cooking and at which point the fat gets rid of toxic molecules, such as acrolein (molecule also present in tobacco smoke).
Although widely used in cooking, animal butter is not the best fat for cooking food. Its cooking point is quite low (120 °C against 160 ° C for oil). Beyond this point of cooking, butter darkens very quickly and becomes toxic.
For cooking meat and fish, vegetable margarine seems to be an interesting alternative. The vegetable margarine withstands high temperatures. But be careful – to make it strong, manufacturers use a process called hydrogenation. “Margarines will have effects on health due to the conventional industrial process which reveals molecules that did not exist in the original product, called trans fats, and increase cardiovascular disease,” says Picot.
It is better never to let oil, butter and margarine, regardless of the fat used, burn at the point of releasing smoke.
If vegetable oils are very good sources of fat, and very good fuel for our body, all do not have the same nutritional value.
Omega 3, Omega 6, biological … olive oil, linseed oil, enriched with vitamins … the number of oils on the market is increasing. So it’s hard to be lost in the jungle of oils!
To choose an oil, one must seek out the omega 3’s – the essential fatty acid category our body does not manufacture. Professor Philippe Legrand, director of the laboratory “Nutrition” at INRA Agrocampus presents the role and importance of omega 3: “Omega 3 are used for growth, they are used for cardiovascular health, brain function, they are strictly necessary.”
We mainly find omega 3’s in canola oil. If you use olive oil, know that it will not help you consume omega 3’s, as confirmed by Legrand: “Olive oil is a fruit oil, the only one that corresponds to a crushed fruit, so it provides antioxidants. But do not expect the olive oil [to be] positive for omega 3 fatty acids because it does not contain it.”
Should we buy oils enriched with vitamins? For Legrand, there are spontaneously in oils antioxidant vitamins such as vitamin E. Some add vitamin D, but this is not a priority or a must because there are other sources of vitamin D, which are not oils.
The fact that oil is enriched with vitamins is not fundamental. But what about organic oils? According to Legrand, bio provides no nutritional value, “there is nothing more in terms of nutrients and health benefits on the nutrition side, however, some may enjoy the tastes and flavors of organic because they have been grown in neater conditions. “
The most important thing for oil is its omega content. To enjoy all the benefits of oil and still have taste, the ideal is to combine: rapeseed oil for omega 3’s, olive oil for its antioxidant side, and why not food argan oil for its smoked side! This oil is a bit more expensive, but it deliciously fragrant for salads and dishes.
(PART II : coming soon)