Many times have you heard about the benefits of omega 3 fatty acids to our health. Cardiovascular protection, reduction of triglyceride reduction, improved mood, mental concentration etc. However, when you go to buy a dietary supplement you wonder whether you should choose a simple supplement with omega 3, cod liver oil or krill oil. But what are the differences and similarities among them? Let’s get to know them a little better!
What are omega 3 fatty acids?
They are a group of polyunsaturated fatty acids that are naturally present in food and can be even synthesized endogenously in our body. There are many different omega-3s, but the majority of scientific research focuses on three, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The human body can not synthesize ALA, but it can partly convert ALA to EPA and then to DHA in the liver. That is why ALA is considered a necessary fatty acid.
Natural sources of omega 3 fatty acids
Omega 3 fatty acids are found in both plant foods, seeds, seafood and fish. ALA is found in plant foods and the richest sources are linseed, soybeans, walnuts and chia seeds. Fish contain various amounts of omega 3 fatty acids, according to the foods they have eaten. Generally, oily fish such as salmon, mackerel, tuna, herring and sardines contain high amounts of omega 3 than lower fat fish. In recent years, with the advancement of food technology, some foods are enriched with omega 3 fatty acids.
Omega 3 fatty acids and dietary supplements
Supplement industry produces dietary supplements with omega 3 fatty acids from natural sources (liver, fish oil, seafood, vegetable oils) and artificially synthesized. Omega 3s are available in various forms such as triglycerides and phospholipids (natural omega 3s) or ethyl ester form (synthetic omega 3s). The safety of all types of omega 3 is proven, what changes however among them is their rate of absorption and bioavailability in the body. Many studies have shown that natural omega-3s have much better absorption and bioavailability than synthetic ones.
Differences among cod liver oil, krill oil and fish oil
Cod liver oil, as its name implies, is the oil that derives from the distillation of cod’s liver. Fish oil derives from the fish tissue, such as shark, salmon or tuna. Krill oil originates from a species of zooplankton in the Antarctic and Arctic regions. The species is called Euphasia Superba and has the appearance of a small shrimp.
Omega 3 concentration
The main difference between fish oil, cod liver oil and Krill oil is their bioavailability of omega 3 fatty acids, their absorption by the gastrointestinal tract and the antioxidant ability of the oil. Although the cod liver oil and fish oils are considered to be very good sources of omega 3 fatty acids, the cod liver oil has a relatively lower concentration of the beneficial fatty acids than fish oils. However, because it derives from the liver, it is rich in fat-soluble vitamins A and D, elements that do not exist in common fish oils. In addition, thanks to vitamin A, which is an antioxidant vitamin, omega 3 fatty acids are protected from oxidation. Krill oil provides higher absorption and better bioavailability of EPA and DHA, while smaller amounts of Krill oil are required, regarding fish oils, to achieve the same concentration and activity of omega 3 in the body. The reason is that fatty acids of krill oil are available in phospholipids rather than triglycerides found in fish and cod liver oil.
Like other fatty acids, Omega 3s are particularly sensitive to oxidation. Cod liver oil, because it contains also the antioxidant vitamin A, has a natural “resistance” against oxidation, which plain fish oils do not possess if they are not enriched with antioxidant substances. Likewise, krill oil, because its omega 3 fatty acids are in the form of phospholipids, are more resistant to oxidation.
Heavy metals – Toxins
With regard to heavy metals and toxins, all if not most companies, ensure the purity of their supplements. Nevertheless, there is a difference in purity and the method of purification, such as double or triple molecular distillation. As far as krill oil is concerned, it is believed to have the lowest burden on toxic substances, as it is at the beginning of the food chain compared to large fish.