Omega-3 Fatty Acids - Features, Effects, and Supplementation

Omega-3 fatty acids are indispensable polyunsaturated fats for the body. They belong to the group of PUFA, which are long-chain (more than 12 carbon atoms) fatty acids. These compounds are exogenous and must be ingested through food. The omega-3 fatty acids include alpha-linolenic acid (ALNA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The latter two, EPA and DHA, can be synthesized in the body from alpha-linolenic acid (ALNA).

Omega-3 fatty acids, which are considered essential nutrients, perform a number of crucial functions in the human body: they decrease blood triglycerides and cholesterol levels, they reduce blood viscosity and flexibility, thereby preventing the formation of clots in coronary and cerebral vessels, they lower blood pressure, they ensure proper growth and development of children and adolescents, they promote healthy skin, hair, and nail formation, they exhibit anti-inflammatory properties, they maintain hormonal balance, they regulate the menstrual cycle, they support the normal development of the fetus, they promote the development of the nervous system and cognitive functions in infants and young children, they prevent the development of insulin resistance and type 2 diabetes, they exhibit antioxidant and anti-allergic properties, they protect against depression. Docosahexaenoic acid (DHA) is the most important omega-3 fatty acid. It is a component of the brain, retina of the eye, and sperm. It improves memory and concentration. It aids in learning and prevents the onset of dementia and neurodegenerative diseases such as Alzheimer's disease. Studies conducted since the 1950s have shown that omega-3 fatty acids have anticancer properties. This process enhances immunity at the cellular level, which is associated with strengthening cell membranes and simultaneously destroying cancer cells.

Omega-3 fatty acids, including DHA and EPA, are found in fish, particularly in fatty species such as herring, salmon, mackerel, and sardines. Plant-based foods are the main source of alpha-linolenic acid. The best sources of alpha-linolenic acid are flaxseed, chia seeds, pumpkin seeds, walnuts, and hemp seeds, as well as rapeseed and soybeans. Omega-3 fatty acids can also be obtained from meat and dairy products from grass-fed animals. High-quality products come from sheep and goats, which often feed on wild herbs and grasses. Table 1 shows the content of alpha-linolenic acid in selected foods, while Table 2 shows the content of EPA and DHA in foods. One of the best sources of alpha-linolenic acid is flaxseed and cold-pressed flaxseed oil. However, it is important to note that omega-3 fatty acids are very sensitive to high temperatures and sunlight, so the oil should be pressed at low temperatures, stored in a dark bottle, and kept in the refrigerator. Before consuming flaxseeds, they should be soaked in water or ground immediately before consumption, as the body does not have enzymes that can digest the thick shell of the seed coat.

An inadequacy of omega-3 fatty acids may result in: developmental delay, skin alterations (such as dryness, thinness, and shedding of the skin), hair loss, poor nail condition, visual disturbances, decreased sebum production by sebaceous glands, increased appetite, impaired heart, liver, and kidney function, development of hypertension, infertility, reduced immunity, allergic diseases, and decreased cognitive function. An excess intake of omega-3 fatty acids may lead to negative health consequences, such as the development of bleeding disorders, degeneration of certain tissues, diabetes, and various infections.

Most Poles do not have access to fresh fish, which are the primary source of DHA and EPA acids. Moreover, fish consumption has been a source of much controversy lately. On the one hand, in stores you can most often find farmed fish that are fed special feeds, which affects the decrease in omega-3 fatty acid content. On the other hand, there is a lot of talk about contamination of fish with sea dioxins, heavy metals, such as lead, cadmium, mercury, and polychlorinated biphenyls (PCBs), which have been included in the WHO's proactive substances. Heavy metals and toxins accumulate in the fatty tissues of fishes. Therefore, the fatter the fish, the more unwanted substances it contains. For this reason, many dietitians recommend consuming leaner species or limiting the consumption of fish and seafood, especially those from highly polluted waters, such as the Baltic Sea. Therefore, supplementation with omega-3 fatty acids is increasingly recommended. In particular, pregnant women, breastfeeding mothers, children and adolescents should definitely supplement with omega-3 fatty acids.