There are many types of fatty acids. Also called Omega 3 and Omega 6, the body needs polyunsaturated fatty acids. This is why they must be regular in foods. Since 2011, their effect on the body prevents cardiovascular disease. Thus, scientific experts have reassessed the situation and advise people to have a higher intake of polyunsaturated fatty acids.
What is polyunsaturated fatty acid?
It is a major constituent of various classes of lipids in the body such as phospholipid and triglyceride. In foods, polyunsaturated fatty acids are present in the form of triglycerides and molecules all grouping 3 acids and 1 glycerol. They are differentiated by the number of carbon atoms that make them up and the type of bonding between them. The latter can be double or single. Only polyunsaturated fatty acids contain at least 2 double bonds.
Once again, these polyunsaturated fatty acids are divided into two large families. Omega 6 is characterised by arachidonic acid and linoleic acid. Omega 3 consists of docosahexaenoic acid or DHA, alpha linoleic acid or ALA and eicosapentaenoic acid or EPA. These fatty acids are important for the body. They are involved in the development and functioning of the human body. This is why it is advisable to include them in food.
Their functions in the body
Polyunsaturated fatty acids form the membranes of all the body's cells in the form of phospholipids. This is why DHA is numerous in the photoreceptors, i. e. the cell membrane of the retina. Then, certain polyunsaturated fatty acids are transformed by the body into different compounds such as thromboxane, leukotriene and prostaglandin. This transformation will modulate various functions such as reproduction, growth, platelet aggregation and the activity of the immune system or neurons. Apart from that, polyunsaturated fatty acids play a regulating role on genes, more precisely those involved in lipid metabolism. They can even be used as fuel to provide energy.
The health consequences of these polyunsaturated fatty acids
Like any other type of fatty acid, polyunsaturated fatty acids do have preventive effects on many diseases.
- Polyunsaturated fatty acids help to prevent cardiovascular disease. The lowering of HDL cholesterol helps to protect the arteries. Through linoleic acid, there is a production of prostaglandins which thus encourage arterial inflammation and the aggregation of blood platelets.
- Secondly, polyunsaturated fatty acids promote the non-deterioration of intellectual capacities. According to scientific analyses, a high intake of EPA and DHA reduces the risk of cognitive decline. If, for example, an elderly person eats fish at least twice a week, he or she will indeed retain a good intellectual capacity and will not suffer from Alzheimer's disease. On the other hand, if there is a deficiency in EPA and DHA, this will disturb the cerebral progression, especially the memorization process.
- For those who feel depressed, whether as a child, young person or adult, supplementation with this type of fatty acid is recommended. It is sufficient to combine it with antidepressant tablets to have a suitable effect.
- The lack of this polyunsaturated fatty acid increases AMD or Age-related Macular Degeneration. If this is not the case, regular consumption of fish will have a protective effect.
- With regard to the development of colorectal cancer, eating fish rich in polyunsaturated fatty acids can protect against this type of pathology. Simply eating 500 mg of fish per day, i. e. two portions of fish per week, is enough to stay healthy. According to other scientific analyses, the consumption of EPA and DHA prevents the renewal of prostate cancer.
Foods containing polyunsaturated fatty acids
In the case of polyunsaturated fatty acids, they are of course found in fat-rich foods. Linoleic acid, a component of these polyunsaturated fatty acids, can be found in foods of plant origin. It is abundant in various oils, nuts and oil seeds. Industrial products containing sunflower oil also contain polyunsaturated fatty acids, such as margarine, ready-made meals, mayonnaise or salad dressing, and crisps.
Since the polyunsaturated fatty acid also has ALA, it is still of plant origin. It is found in seeds, nuts, some oils, fruits and vegetables. The flesh of herbivorous animals such as rabbits also contains it. Dairy products, eggs, meat and sausages also contain polyunsaturated fatty acids.
EPA and DHA are found in seafood such as oily fish. Canned cod liver contains more polyunsaturated fatty acids. It contains 4060 mg of DHA and 3080 mg of EPA.
Intakes recommended by health professionals
Since 2011, health experts have noted that the body needs an intake of polyunsaturated fatty acids. For children aged between 6 months and 3 years, the body should contain 3 g of LA, i. e. 2. 7% of energy intake, 0. 5 g of ALA, i. e. 0. 45% of energy intake, 70 mg of DHA and maximum 70 mg of EPA. For children over 3 years of age, it is essential to give 4% of energy intake, i. e. 6. 7 g of LA, 1. 7 g of ALA, i. e. 1% of energy intake, 125 mg of DHA and 125 mg of EPA. Finally, for pregnant women, teenagers and adults, it is preferable to have 4% or 8. 8 g of LA, 1% or 2. 2 g of ALA, 250 mg of DHA and 250 mg of EPA.
According to the ANSES recommendation, it is essential to consume 2 to 3 tablespoons of oil enriched with ALA every day or to eat 2 portions of fish per week. It is also possible that these intakes are improved by the appropriate choice of fats and the habitual intake of seafood and fish.
