What are omega 3s?
The omega 3 (ω3), as well as the omega 6 (ω6), are essential fatty acids (AGE). These are molecules that our body is NOT able to synthesize independently; for this, it is necessary to take them through the foods that are rich in them.
The omega 3s have different functions; in balance with omega 6, they regulate inflammatory reactions, platelet aggregation, vasodilation and blood coagulation. Moreover, it appears that they are partially responsible for the lipemic state (ratio between the plasma lipoproteins and the total amount of triglycerides). A good supply of omega 3 promotes the prevention of atherosclerosis and of cardiovascular inauspicious events (myocardial infarction and cerebral stroke, respectively caused by hypertension, hyperlipemias and chronic hyperglycemia), since they also act on the regulation of arterial pressure and trigger mechanisms of atherosclerotic plaque. Their anti-inflammatory activity could also be beneficial in the prevention and proper management of chronic inflammatory diseases.
According to the LARN guidelines, the supply of essential fatty acids with the diet should be around 2.5% of total calories, respectively supplied at 2% by ω6 and at 0.5% by ω3. We therefore recommend a ratio of 4: 1 even if, according to research statistics, it seems that in the diet of Italians this balance tends to be high.
Some data report a ratio of even 11: 1 or higher. The fear of the researchers is that the excessive presence of omega-6 may favor the inflammatory response (in the opposite way the omega 3), even if the most recent "in vivo" tests deny this hypothesis and identify in ω6 a function very similar to that of the omega 3.
Food sources of omega 3 - oils
The omega 3 are present in foods of both animal and vegetable origin, but they are present in different prevalent chemical forms. In fish, especially the one called "blue", EPA and DHA (eicosapentaenoic and docosahexaenoic - biologically more active for the human organism) stand out, while in vegetables (ESPECIALLY IN SOME COLD COLD OILS) the α-linolenic acid is highlighted (biologically less active but still very useful for achieving the recommended ration). However, this is an unclear distinction and the composition of some products is far from what was generally said.
Therefore, in addition to regularly consuming good portions of fish rich in omega 3 (anchovies, sardines, mackerel, lanzardo, bonito, tuna, lampuga, leccia, ricciola, greenhouse, alletterato, needlefish, boga, salmon, cod etc.), it is possible significantly increase the intake of these nutrients by consuming vegetable or animal extracted oils.
It is good to keep in mind that omega 3s are very delicate fatty acids and tend to degrade very easily. This, in addition to giving an odor and a taste that is anything but pleasant, frustrates the metabolic effect on the body. Omega 3 is very sensitive to oxidation / peroxidation when exposed to air, light and heat; moreover, they tend to dilute considerably in other lipid solutions, dispersing in them.
Fish oils rich in omega 3
Among the oils richest in omega 3 extracted from animals we mention: cod liver oil and krill oil (which is also very rich in vitamin D). While the former is taken from the hepatic organ of the fish, the latter is derived from zooplankton, which represents the first link in the marine food chain. This clarification is rather important; taking omega 3 with fish has a small drawback compared to krill and vegetable oils, or contamination from some environmental pollutants. Obviously, the commercially available cod liver oils are strictly controlled so that the concentration of mercury and lead, where present, always falls within the safety limits. On the other hand, it is good to remember that the presence of such "undesirable" should be estimated on the overall diet and that the share of lead and mercury possibly present in cod liver oil should be added to that of high foods. To overcome this drawback it is possible to prefer krill oil or vegetable oil.
Cod liver oil and krill oil are not used for food purposes and tend to be taken as food supplements by means of "gelatinous pearls". The liquid intake of fish oil is extremely unpleasant; who in the past (especially our grandparents) had to take cod liver oil as a prevention against rickets (thanks to the high content of vitamin D) will still clearly retain the memory of an almost traumatic experience.
The indicative composition of omega 3 fish oils is:
- Krill oil: 30% omega-3
- Cod liver oil: 20% of omega-3
Vegetable oils rich in omega 3
If fish oils are considered mainly dietary supplements, vegetable oils are (and vary) contemporary food. It is well known that the use of oil rather than butter or lard is a good food habit. But are we sure of that? Indeed, by analyzing the composition of certain low-cost commercial oils, some doubts arise. These (for example palm oil or mixtures of oils extracted with chemical or heat), in addition to being almost completely free of omega 3, are instead rich in saturated or hydrogenated fatty acids and even in "trans" conformation; in short, real bad fats.
Let us dwell instead on good oils, those rich in omega 3 (as well as vitamin E); of these, a good part has been recovered from tradition and popular use (even archaic). Contrary to what one might believe, most of the vegetable oils rich in omega 3 are of medium or low organoleptic and gustatory value (nothing to do with the magnificent extra virgin olive oil which, for its part, does not boast a similar concentration of acid α-linolenic acid). They are to be used raw, never for cooking, and absolutely not for preservation in oil. These must be kept in the dark, in the refrigerator and possibly in containers from which it is possible to extract the air or in any case hermetic; vegetable oils rich in omega 3 always have fairly short deadlines.
Some vegetable oils rich in omega 3 are:
- Seaweed oil: it seems to contain about 100% of omega 3 fatty acids (also made up of DHA), but the sources are not certain
- Kiwi oil: 60% of omega 3
- Linseed oil: 50% of omega 3
- Hemp seed oil: 15-20% of omega 3
- Rapeseed and / or rape oil and / or canola oil: 5-16% of omega 3
- Walnut oil: 10% of omega 3
- Soybean oil: 8% of omega 3.
