Functions of Omega 3
Some of the biological functions of omega 3s are:
- Constituents of cell membranes,
- They structure the nervous and ocular tissue,
- Precursors of anti-inflammatory eicosanoids,
- They counteract hypertension and hypertriglyceridemia (with beneficial effects on vascular health),
- They participate in maintaining brain function even in old age,
- They protect against certain degenerative eye diseases,
- They should reduce the symptoms of rheumatoid arthritis,
- They improve mood by hindering certain forms of depression.
Having said this, it could be deduced that omega 3 deficiency negatively affects body homeostasis, predisposing to various discomforts or pathologies. This is why, in addition to suggesting a greater consumption of foods that contain them, some professionals recommend dietary supplementation. However, it would be useless (or wrong) to resort to this strategy without changing one's eating habits; ergo, to avoid the deficiency, it is first of all necessary to increase the consumption of foods rich in omega 3. Later we will understand better how to do it, but we specify immediately that it is a dietary correction that is anything but simple or trivial; to increase the "Omega 3 intake, in fact, it is not enough to increase the food consumption of the latter, but it is also necessary to evaluate the following factors:
- Type of omega 3: not all omega 3s are the same and some are more useful than others,
- Essential fatty acids is not synonymous with omega 3: omega 6 are also essential, which however, due to their greater presence in foods, are almost never potentially deficient.
- Ratio between omega 3 and omega 6; the excess of omega 6 can compromise the metabolic balance or counteract the endogenous synthesis of certain omega 3,
- Integrity of omega 3: omega 3 are delicate nutrients and do not always reach our tables intact,
- Portions of foods rich in omega 3: they are not free, as foods that contain more omega 3 also have contraindications.
It is commonly believed that omega 3s are all essential nutrients (which the body does not produce on its own). In fact, the only truly essential omega 3 is alpha linolenic acid (ALA), from which the human body derives the active metabolites eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Given the precariousness of this latter process, some define EPA and DHA conditionally, potentially or semi-essential.
Recall that in nature there are other types of omega 3, which however do not have the same nutritional importance (eg. Hexadecatrienoic acid, octadecatetraenoic acid, etc.).
.Alpha linolenic, eicosapentaenoic and docosahexaenoic acids do not have the same food sources.
While ALA is mainly contained in foods of plant origin, EPA and DHA are more abundant in foods of animal origin.
Let's go into more detail.
Foods rich in Alpha Linolenic Acid (ALA)
Foods rich in alpha linolenic acid are mainly oil seeds or their germs. From these you can extract the oil, which is a real concentrate of fats. However, often these foods also contain many other different fats, such as omega 6 and omega 9.
Some natural unprocessed foods are rich in alpha linolenic acid such as: chia seeds, kiwi seeds, perilla seeds, flax seeds, cranberry, camellia, porcelain, sea buckthorn, hemp, walnut, canola and soy.
Secondly, as they are richer in omega 6 or omega 9, they are: almonds, pine nuts, pistachios, pecans, Brazilian nuts, hazelnuts, cashews, sunflower seeds, pumpkin etc.
Small concentrations of ALA are also present in vegetables and fruit in general.
Foods extracted from the aforementioned natural sources are even MORE "rich in alpha linolenic acid; for example, the germ of cereals, such as wheat germ, or extraction oils: chia oil, kiwi oil, perilla oil, etc.
Foods rich in Eicosapentaenoic and Docosahexaenoic Acids (EPA and DHA)
Foods rich in eicosapentaenoic and docosahexaenoic acids are mainly: fishery products, especially the organisms that populate cold waters and blue fish in general, their liver, krill and algae; from the liver of fish, krill and algae it is possible to extract the oil which, to date, represents the most abundant source of EPA and DHA.
However we must remember that aquatic organisms are potentially subject to environmental pollution by mercury, dioxins etc; this feature requires managing its consumption, avoiding exceeding the recommended doses and frequency, preferring less contaminated foods and supplements that have one or more quality certifications.
They are rich in eicosapentaenoic and docosahexaenoic acid "fresh, unprocessed foods" such as: sardine, mackerel, tuna, bonito, garfish, lanzardo, horse mackerel, sardinella, herring, cod, salmon, anchovy, sea lettuce, wakame seaweed, etc.
High concentrations of EPA and DHA are also present in dried algae such as nori and kombu (even if conservation penalizes the integrity of polyunsaturated fats) and canned fish.
The "foods extracted" and / or "processed" by the aforementioned foods are even MORE "rich in alpha linolenic acid; for example cod liver, salmon roe, mullet, flying fish, sturgeon, bottarga, "cod liver oil, salmon oil" etc.
They do not come from real foods and are classified as supplements ONLY: krill oil, spirulina algae, algae oil etc.
In some countries, especially in the Nordic countries but not only, the meat of the cetaceans, the oil obtained from it and the seal oil are also consumed. Note: the hunting of some of these animals is prohibited today.
Summary table of foods rich in Omega 3
Which foods rich in Omega 3 should you prefer?
Difficult to say; the criteria of a "healthy and balanced diet are not limited to assessing the concentration of omega 3 in foods and many other factors take over. However, considering that ALA, EPA and DHA have partially different functions, as is their presence in foods , the following should be considered.
Alpha linolenic acid, present only in foods of plant origin, is the only truly essential omega 3; however, in the organism it mainly plays the role of precursor of EPA and DHA (not essential but metabolically active). It is also the most abundant omega 3 in the diet, while the other two are limited to "underwater" products.
Considering that the transformation of ALA into EPA and DHA is a process that uses the same enzyme used for the switching of omega 6 (more abundant in the diet), it is reasonable to assume that this process is NOT sufficient to cover the nutritional needs of EPA and DHA. Moreover, unlike plant foods, fishery products and algae do not contain higher quantities of omega 6, which facilitates the maintenance of the right ratio between omega 3 and omega 6 in the diet.
For all these reasons, when choosing foods rich in omega 3, it is advisable to prefer nutritional sources that contain EPA and DHA: fish, fish liver, fish oil, fish liver oil, algae, algae oil and oil of krill.
with high biological value, certain B vitamins and specific minerals. The meat of terrestrial animals, offal, derivatives and eggs (which are part of the same group) also participate in this function; not only that, the second fundamental group, that of milk and derivatives, also contributes to the same purpose.
For their part, fishery products are also rich in vitamin D and iodine, nutrients potentially lacking in the collective diet; however they may contain, especially large ones, dangerous pollutants, such as mercury and dioxins. In addition, too much protein can upset the balance of the diet. This requires:
- Alternate the consumption of fishery products with meat, cheese and eggs,
- Carefully compare the portions and the frequency of consumption of high protein foods (I and II fundamental food group), without forgetting that even cereals and legumes can provide considerable quantities of peptides,
- Limit the consumption of large fish to "one-off", preferring small creatures, which contain less pollutants,
- Consume portions of 150 g referring to fresh foods and 50 g for those preserved,
- Regarding supplements, such as fish, krill or seaweed oil, make sure:
- That has appropriate certifications such as IFOS (International Fish Oil Standard),
- To keep it carefully,
- Not to exceed the dosage, consulting your doctor, pharmacist or following the instructions on the label.
Retain Omega 3
Foods rich in omega 3 and supplements need to be stored properly. We have already said that these lipids fear oxygen and free radicals, heat (cooking) and light.
As for fresh fish products, the only way to preserve them carefully is freezing; in the refrigerator they have a very short time limit for consumption. With regard to processed or extracted products, such as bottarga and fish oil, it is advisable to keep them in the dark, cool and in airtight packages; they can also be placed in the freezer or in the refrigerator. The same applies to vegetable oils and grains rich in fat; many prefer to store the seeds in glass jars at room temperature, in plain sight, but this does not facilitate their storage.
Omega 3s are also sensitive to cooking; the oils that are rich in it are NOT suitable for cooking and the food ones (not supplements such as seaweed, fish and liver oil) should be used as a raw condiment.
Foods rich in omega 3 such as fish and seeds should be consumed after rapid cooking, not too intense; frying is therefore absolutely not recommended.
