Omega-3 fatty acids are exclusively beneficial and essential for health. It’s no coincidence that they are sometimes referred to as “vitamins”.
(In the strict sense, they are not, but the term correctly emphasizes their important role: “vitamin” – essential for life.)
In this article, we have prepared a guide on how to properly take omega-3. We will discuss:
- how much omega-3 is needed per day (dosage);
- the advantages of capsule supplements compared to fatty fish;
- who is at risk of omega-3 deficiency;
- how likely and dangerous deficiency is for vegans and vegetarians;
- the harm of omega-3 in excessively high doses.
Main thoughts:
Brief Introduction to Omega-3: What Everyone Should Know Before Taking Omega-3
Omega-3 fatty acids belong to the class of polyunsaturated essential fatty acids. “Essential” means that they must be present in the diet for the body to function properly.
Not all omega-3s are equally beneficial.
There are three main forms of omega-3: ALA, EPA, DHA. ALA is the inactive form of omega-3 and must be converted into EPA and DHA within the body. The conversion efficiency is very low (~5%).
Therefore, omega-3 in the form of ALA should never be the sole source of these fatty acids.
Omega-3 in the form of ALA is mainly found in plant products: flaxseed and oil, walnuts, chia seeds, soy.
EPA and DHA are the two active forms of omega-3 that are directly responsible for their beneficial properties. Their sources include fatty fish, fish oil, krill oil; however, they are initially synthesized by marine algae, which serve as food for marine inhabitants and, after absorption, become structural elements of tissues 1.
Omega-3s are active structural components of the body’s cells, including some of the most important organs and systems: the brain, nervous tissue, eyes, sperm.
“Active” in this context means that they not only form the structure of cell membranes but can also leave them under certain conditions (such as stressors like inflammation or pain) to perform beneficial functions.
Thus, they participate in the formation of special signaling molecules (eicosanoids), which are very similar in structure to omega-3 fatty acids and have anti-inflammatory effects, which explains many of the beneficial properties of omega-3s in the body (for the cardiovascular, immune, endocrine, and nervous systems), as most diseases are accompanied by inflammatory processes.
Recommended: To learn more about what omega-3 fatty acids are, their different forms, and beneficial properties based on scientific research, read the article What Are Omega-3 Fatty Acids Good For? Scientific Facts.
How to Properly Take Omega-3 Fatty Acids
To meet the daily requirement of omega-3 fatty acids, there are two ways: foods rich in omega-3 and dietary supplements.
Often, expert recommendations on how to properly take omega-3 boil down to a simple rule: eat fatty fish at least twice a week 33.
The most beneficial fish in terms of omega-3 content are salmon, mackerel, tuna, herring, and sardines. Detailed information about natural products rich in omega-3 can be found in the article Which Foods Contain Omega-3 (Table).
The omega-3 content in fish is determined by the food it is fed. This is why farmed salmon (aquaculture) and wild salmon have different amounts of omega-3: farmed salmon generally contains a bit more 2,3. Why? Because their feed contains more of it.
There is very low omega-3 content in beef and other meat-dairy products. However, if animals are raised in natural free-range conditions on pastures, the omega-3 fatty acids in their meat are higher 4.
Today, many food manufacturers enrich their products with omega-3 in the form of DHA. This includes eggs, yogurt, milk, and soy products. Naturally, it is better to prefer these.
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Omega-3 Dosage Per Day
It is important to understand that the recommended daily dose of omega-3 is a very relative figure, which is a natural consequence of the ambiguity of scientific research results regarding their effectiveness: very often, when using the same dose, scientists obtain different results, or in some experiments, the effect may be positive at low doses, while in others, it may be at high doses. For illustration, see What are omega-3 fatty acids good for? Scientific research.
This fact is particularly evident in the significant differences in the daily doses of omega-3 recommended by leading health organizations: it ranges within a fairly wide range from 250 to 2000 mg per day 5,6:
- World Health Organization – 2000 mg per day;
- U.S. Department of Health – 500 mg per day.
At the same time, the U.S. Food and Drug Administration (FDA) considers the safe limit (maximum dose) to be 3000 mg per day 6.
It is important: this refers to the active forms of omega-3 DHA and EPA.
For pregnant and breastfeeding mothers, it is recommended to increase the daily dose of omega-3 by at least 200 mg (in the form of DHA) per day 9, as they are very important for fetal development.
It is also important to keep in mind that the dose of omega-3 is largely determined by how much omega-6 is in the diet: the more omega-6, the more omega-3 is needed.
The general recommendation regarding the daily dose of omega-3: 500-2000 mg (in active forms of EPA and DHA) or consuming fatty fish twice a week
Omega-6 in Your Diet Affects the Required Dosage of Omega-3
In one study, it was shown that when the diet increases the proportion of omega-6 rich foods, the beneficial property of omega-3 that lowers blood triglyceride levels, which is associated with an increased risk of cardiovascular diseases, significantly decreases.
The same fish with the same content of health-beneficial omega-3 fatty acids EPA and DHA, but different ratios of omega-6 to omega-3, has different effects on cardiovascular disease risk factors: blood triglyceride levels (thrombus formation) and inflammatory processes 10,11.
The average Western diet contains 10-15 times more omega-6 fatty acids than omega-3. The main sources of omega-6 are refined vegetable oils, which are added to processed foods (sunflower, palm, etc.) 12,13.
Experts argue that this ratio should not exceed 2:1 (omega-6:omega-3) 14.
The point is that both types of fatty acids seem to compete with each other: they require the same enzymes for conversion into active form: the more omega-6, the less share of enzymes is available for omega-3 15,16.
In other words, if the diet has a lot of omega-6, a higher dosage of omega-3 is needed.
The reverse also works: reducing the amount of omega-6 decreases the required amount of omega-3.
For optimal health, the balance between omega-3 and omega-6 fatty acids in the diet is more important. The ideal ratio is 2:1 (omega-6: omega-3). However, statistics show that in the diet of the average Western person, the balance is disrupted and is approximately 15:1.
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How to take omega-3 in capsules. Omega-3 dosages in capsules
Omega-3 dietary supplements are another good alternative source of health-beneficial active forms of omega-3 EPA and DHA.
Most scientific studies highlighting the benefits of omega-3 specifically use dietary supplements.
The best omega-3 capsule products are those made from fish oil, krill oil, and cod liver oil. For vegetarians, there is a worthy alternative – omega-3 supplements based on algae.
Both types contain omega-3 in active forms EPA and DHA and are very well absorbed.
A fish oil capsule typically weighs 1000 mg and contains about 180 mg of EPA and 120 mg of DHA. However, omega-3 dosages vary widely among products from different manufacturers 17.
Pay attention to the difference in the mass of the omega-3 capsule and the fatty acids it contains: it is very important to pay attention to the mass content of EPA and DHA in each capsule when purchasing. Sometimes the manufacturer may indicate the mass of fish oil in the capsule, which is NOT equivalent to the mass of omega-3 fatty acids.
Cod liver oil, in addition to omega-3, contains quite large doses of vitamins A and D. On one hand, this is good. On the other hand, it is important to always keep this in mind to avoid overdose: an overdose of vitamin A can be harmful to health.
Today, many types of fish have a high level of contamination with toxins and heavy metals, particularly mercury and lead. One of the undeniable advantages of omega-3 supplements is that they are usually purified from toxins and heavy metals during the manufacturing process 18.
For more information about omega-3 supplements, their varieties, advantages, and disadvantages based on scientific research, read the article Which omega-3 supplements (capsules) are the best: how to choose and what to buy.
Those who do not regularly consume fatty fish and other seafood are recommended to additionally take omega-3 supplements in capsules
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Which omega-3 supplements to take for vegans/vegetarians
Despite the fact that there are quite a few plant-based products containing omega-3 in significant amounts (flax seeds and oil, chia, walnuts, sesame, etc.), as mentioned earlier, all of them are sources of the inactive form of omega-3 – ALA – the effectiveness of which is very low, as are its beneficial properties.
The majority of omega-3 supplements available in pharmacies are made from fish, so they are not suitable for strict vegetarians (vegans).
However, there is a wonderful alternative for vegetarians – omega-3 supplements based on phytoplankton (algae) – the very source from which omega-3 fatty acids enter the bodies of fish and shellfish, including krill.
Such supplements are an excellent and probably the only plant-based source of effective forms of omega-3 DHA. In terms of their beneficial properties and absorption rates, they are close to fish oil 19-22.
Vegetarians and vegans are recommended to take omega-3 supplements in capsules based on microalgae (phytoplankton): they are absorbed as well and are as beneficial as fish oil capsules
Omega-3 deficiency. Symptoms. Risk of acute deficiency in vegetarians and vegans
Scientists note that in the case of a deficiency of omega-3 in active forms (DHA and EPA) in the diets of vegetarians, complete depletion of their levels in the blood does not occur, as the body adapts and increases the production of active forms of omega-3 (DHA and EPA) in the liver from the inactive form (ALA), found in many plants 23,24.
Also, during periods of poor nutrition or diets that create an energy deficit, the body begins to use fat stored in fat reserves for energy, while simultaneously releasing omega-3 25.
With an increase in the amount of omega-3 (DHA and EPA) in the diet, their synthesis by the body decreases. This is an adaptive mechanism, which likely explains the fact that a critically dangerous deficiency of omega-3 is almost never observed.
In the blood of vegans and vegetarians, the level of active forms of omega-3 fatty acids (EPA and DHA) is generally reduced, but a critical deficiency never develops due to the adaptation mechanism that increases the synthesis of omega-3 in the body.
However, experiments on animals have shown that acute deficiency of omega-3 (DHA) in vital organs (retina and brain) is possible after restricting them in the diet for several generations, which manifests as impaired vision and brain function in offspring 26-28.
A deficiency of omega-3 that is dangerous for the function of vital organs and tissues (brain, retina) can develop as a result of a lack of omega-3 in the diet over several generations. Its result may be impaired vision and brain function in new generations.
With a deficiency of omega-3 (DHA) in the diet, their concentration in the brain decreases by 30%-50% (the lower limit corresponds to a diet high in plant omega-3 (ALA), the upper limit to a low one) 29.
This depletion of omega-3 occurs with a prolonged deficiency of omega-3 in the diet from 18 months to 5 years and is further accelerated by alcohol consumption 30,31.
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Symptoms of acute omega-3 deficiency 32:
- thickening of the skin;
- dermatitis;
- decrease in the level of omega-3 in the form of DHA in the blood and tissues.
Omega-3 in capsules made from krill oil and fish oil can be purchased at ru.iHerb.com. The iTested option on the left panel allows you to display supplements tested for quality in an independent laboratory.
Risk Groups for Omega-3 Deficiency
As noted above, an actual omega-3 deficiency is a very rare occurrence 32 due to the body’s adaptive mechanism and its ability to synthesize active forms of omega-3 (DHA, EPA) from inactive ones (ALA), as well as releasing them from fat stores.
Therefore, the risk group for omega-3 deficiency includes only those individuals whose parents did not consume enough omega-3 (in the form of DHA) or, even worse, several preceding generations of whom had a deficiency of these fatty acids in their diet.
Also included in the risk group for omega-3 deficiency are children who were fed infant formulas lacking omega-3 in active forms (DHA and EPA). An example is infant soy formulas, where omega-3 is present in the form of ALA.
At risk for acute deficiency are children who were fed formulas lacking omega-3 in active forms (DHA and EPA), as well as those whose parents, grandparents, etc., consumed them insufficiently.
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Harm of Omega-3: Excessive Daily Doses of Omega-3 Can Be Dangerous to Health
According to FDA (Food and Drug Administration) data, a daily dose of omega-3 of 3000 mg is considered safe 6.
According to the European equivalent of the FDA – EFSA – daily doses of omega-3 up to 5000 mg do not pose a health risk.
What is the basis for establishing an upper limit?
Excessive daily doses of omega-3 can thin the blood, which manifests as excessive bleeding when open wounds occur or in certain medical conditions.
That is why doctors often recommend excluding omega-3 from the diet of patients who are scheduled for surgery several weeks prior to the procedure.
Another reason to limit the dose of omega-3 is the high risk of vitamin A overdose, which is present in many fish oil and cod liver oil supplements, and an overdose of which can be dangerous to health.
In scientific experiments studying the benefits and harms of omega-3, doses exceeding 5000 mg are almost never used.
Omega-3 is considered relatively safe for health. However, excessively large doses of omega-3 per day (over 3000 mg) can be harmful, as they have a blood-thinning effect and increase the risk of vitamin A overdose.
