Fish oil has been used in medicine for centuries to improve health, although the mechanisms behind its beneficial effects were only discovered in the second half of the 20th century. We now know that it contains omega-3 polyunsaturated fatty acids (PUFAs), which affect the cardiovascular system and inflammatory processes in the body. In this article, we'll explain why omega-3 matters for the body and what it's needed for, which areas of medicine use it, where to get PUFAs, and what dose to take.
Why Omega-3 Matters and What It's Needed For
Omega-3 fatty acids are essential fatty acids. This means the body cannot make them on its own. They can only be obtained from food.
Most people are deficient in omega-3, because it's found in plant oils and fatty fish that people rarely eat, as well as in seafood. About 80% of the population in developed countries has an omega-3 deficiency.
The biological role of omega-3 lies in its involvement in the biochemical reactions of cyclo- and lipoxygenation. In these processes, arachidonic acid gives rise to thromboxane, which narrows blood vessels, promotes the aggregation (clumping) of platelets, and acts as a trigger for inflammatory reactions. Together with omega-6 fatty acids, omega-3 mainly regulates three processes in the body: inflammation, vessel diameter, and platelet aggregation, which is important for blood clot formation.
Omega-3 and omega-6 compete with each other, which is why their ratio in the body matters. In most cases omega-6 predominates, and this has a negative effect on health. This ratio needs to be corrected. When the share of omega-3 increases, it leads to vessel dilation, "thinning" of the blood, and a reduced inflammatory response. Omega-3 also affects blood triglyceride (fat) levels, the heart's electrical stability, and the dissolution of blood clots.
A Cure for Every Disease?
When a drug — and especially a supplement — is marketed as a cure for every disease, it immediately raises a red flag for the buyer. Indeed, many things that supposedly help with everything actually help with nothing.
With omega-3, however, the story is different. These polyunsaturated fatty acids are genuinely used in many areas of medicine, play an important role in preventing and treating disease, and their effect is clinically proven.
Liver. Fatty liver, steatohepatitis, fibrosis, and cirrhosis are conditions that omega-3 PUFAs don't just help prevent — they can also help reverse them (back to a normal liver), at least at the stage of hepatic steatosis. Taking omega-3 also lowers the risk of liver cancer. Regular omega-3 intake reduces blood ALT levels, the main marker of liver damage.
Joints. Regular omega-3 intake helps reduce the clinical symptoms of rheumatoid arthritis, osteoarthritis, and reactive arthritis. The effect is linked to a reduction in the production of eicosanoids — pro-inflammatory cytokines.
Immune conditions. Studies show a benefit from adding omega-3 to standard therapy for systemic lupus erythematosus, psoriasis, and atopic dermatitis. In these conditions, arachidonic acid levels in the skin are on average 8 times higher than normal. Omega-3 counteracts the pro-inflammatory effects of arachidonic acid metabolites (prostacyclin, leukotrienes, lipid peroxides).
Kidneys. Regular omega-3 intake slows the progression of chronic kidney disease by reducing the rate of glomerular sclerosis.
Cancer. Studies in Japan and Greenland found a lower risk of breast cancer compared to average population rates, and this effect is thought to be linked to high consumption of fatty fish and seaweed rich in omega-3.
Skin. Eicosapentaenoic acid is especially beneficial. It reduces sebum production, lowers the risk of acne, increases skin hydration, and protects skin from photoaging by suppressing the formation of substances that break down collagen (the protein that gives skin its firmness).
Brain. There is evidence that omega-3 slows the progression of Alzheimer's disease, improves sleep quality in children, and reduces depression and anxiety. In patients with bipolar disorder and schizophrenia, omega-3 reduces the frequency of relapses.
Pregnancy. The Russian Society of Obstetricians and Gynecologists recommends omega-3 for pregnant women. Studies show a positive effect on brain and vision development in children whose mothers did not have an omega-3 deficiency during pregnancy. During fetal development, children have a lower risk of intrauterine growth restriction and fetal hypotrophy, and after birth, a lower risk of ADHD, autism, cerebral palsy, and behavioral problems. These children also tend to have better communication skills and a higher IQ.
Omega-3 and Cardiovascular Disease
We've discussed what the body needs omega-3 for and which disease risks it affects. But the cardiovascular system deserves a section of its own, since it's in cardiology that PUFAs are used the most.
In the 1980s, Danish scientists I. Dyerberg and H. Bang noticed that cardiovascular disease was rare among the native population of Greenland. It turned out that the secret to their "clean vessels" was a high intake of omega-3 — ten times higher than the average European level.
Today, in Europe and the US, omega-6 intake exceeds omega-3 intake by 30–40 times on average, and the prevalence of cardiovascular disease is 45%. Among Greenlanders, the ratio is 1:1, and heart disease prevalence is just 7%. Later studies established that for optimal health, the omega-6 to omega-3 ratio should be at least 3:1 — never 40:1, as it is for most people.
Does this actually work in practice? Yes, and it's been confirmed by numerous studies:
- The Cardiovascular Health Study, involving 4,738 patients over age 65, showed a 20% reduction in heart failure risk among those who ate fish 1–2 times a week, and a 31% reduction among those who ate fish 3–4 times a week.
- A study by H. Iso et al. showed a twofold reduction in stroke risk among women who ate fish 2–3 times a week.
- The American Physicians' Health Study found that blood omega-3 levels were inversely related to the risk of sudden cardiac death in men.
- A study by D. Kromhout et al. showed that even a small daily amount of fish reduces the risk of death from coronary heart disease (including myocardial infarction) by 50% over 20 years, compared with people who eat no fish at all. These findings were confirmed by the large-scale MRFIT study.
- The Zutphen Study found that just 20 g of fish a day reduced stroke risk in men by 51%.
To achieve adequate omega-3 intake and a healthy ratio with omega-6, you don't need to switch to a diet of seaweed and seafood. Taking omega-3 supplements regularly is enough.
Sources of Fatty Acids
We've established why omega-3 matters. Now let's look at which sources can provide the omega-3 fatty acids you need.
The minimum amount of fish needed to help prevent cardiovascular disease is 30–40 g per day. This amount provides 600–800 mg of omega-3 per day.
In Western countries, average fish consumption is only 1–13 g per day. And even that fish doesn't deliver 100% of its benefit, because only baked or boiled fish is a good source of omega-3 — not fried, since frying damages long-chain fatty acids and changes their biological properties.
Not all types of fish are good sources of omega-3. Deep-water fish that live in cold waters contain the most PUFAs: salmon, mackerel, herring, tuna, and trout, as well as whitefish, nelma, sturgeon, and peled.
The table below shows the omega-3 content of various foods.
| Food | EPA and DHA content per 100 g of product (serving size) | Amount of product providing 1 g of EPA and DHA |
|---|---|---|
| Tuna (fresh) | 0.28–1.51 | 66–367 |
| Atlantic salmon | 1.28–2.15 | 42.5–70.9 |
| Mackerel | 0.4–1.85 | 54–250 |
| Atlantic herring | 2.01 | 50 |
| Rainbow trout | 1.15 | 87 |
| Sardines | 1.15–2.0 | 50–87 |
| Halibut | 0.47–1.18 | 85–213 |
| Tuna (canned) | 0.31 | 323 |
| Cod | 0.28 | 357 |
| Haddock | 0.24 | 417 |
| Catfish | 0.18 | 556 |
| Carp | 1.00–1.10 | 91–100 |
| Perch | 0.20–0.60 | 167–500 |
| Flounder or sole | 0.49 | 204 |
| Salmon | 1.00–1.40 | 71–100 |
| Oysters | 0.44 | 227 |
| Shrimp | 0.32 | 313 |
| Scallops | 0.2 | 500 |
| Crab | 0.20–0.40 | 250–500 |
You can also get omega-3 from plant sources. Flaxseed oil contains alpha-linolenic acid, which the body converts into eicosapentaenoic and docosahexaenoic acid. Omega-3 is also found in rapeseed and camelina oil, and in walnuts.
How Much Omega-3 Should You Take?
If fish rarely appears on your plate, you can get omega-3 from supplements. How much you need depends on your goal — treatment or prevention:
- The minimum daily dose for preventing atherosclerosis, and for pregnant women, is 300 mg (0.3 g) a day.
- Russia's Institute of Nutrition recommends 0.8–1.6 g of omega-3 a day.
- Treating hypertriglyceridemia or recovering from a myocardial infarction calls for 2 to 4 g a day.
Which supplements can you use:
Flaxseed oil. Cold-pressed, unrefined flaxseed oil, 250 ml. It's one of the richest plant sources of omega-3 — in terms of alpha-linolenic acid content, flaxseed oil actually surpasses fish oil. The standard dose is one tablespoon (about 15 ml) a day; the oil isn't suitable for cooking and should only be used cold.
Omega 3-6-9 Iconfit. 90 capsules, each containing 1 g of fatty acids, of which 250 mg is omega-3 (EPA and DHA). The instructions call for one capsule a day, but the minimum dose recommended by most medical organizations is 300 mg a day, so it's better to use a higher-dose supplement.
Pumpkin seed oil. Capsules made with pumpkin seed oil, rich in omega-3 and vitamin E. Ingredients: pumpkin seed oil only. This supplement supports heart health, healthy skin, and a stronger immune system. Dosage: 4 capsules, 3 times a day, with meals. Course: 1–2 months. Per capsule: omega-3 — 1,500 mg (13.5% of the daily value), vitamin E — 50 mg (15% of the daily value).
Omega 3-Vitum Forte. 60 capsules, each containing 1,100 mg of fish oil, of which 363 mg is eicosapentaenoic acid (EPA) and 242 mg is docosahexaenoic acid (DHA). Adults take 1–2 capsules a day to support heart, brain, and eye health, or 2 capsules twice a day to help maintain normal triglyceride levels. The capsules also contain vitamin E.
Although most supplement instructions recommend taking omega-3 for just 1–2 months, such a short course doesn't really make sense. Omega-3 isn't a medicine — it's a nutrient that's essential for life. PUFAs should be taken for life, or at least until fish becomes a daily guest at your table.
All fatty-acid supplements are in the "Omega-3 and fatty acids" section, and cold-pressed plant oils in "Edible oils".
Important information
Food supplement. NOT A MEDICINE. Do not exceed the recommended daily dose. A food supplement should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Before use — especially during pregnancy, breastfeeding, while taking medication or with any medical condition — consult a doctor. Do not use in case of intolerance to any of the ingredients. Keep out of the reach of children.
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