Omega−3 fatty acids have been known as essential to health and development since 1929 when George and Mildred Burr reported that deficiency of omega-3’s caused disease in rats fed a fat-free diet. Awareness of their health benefits, however, has really increased since the 70s, when researchers tried to explain the so-called “Inuit-” or “Eskimo paradox”. How can arctic natives who gorge on fat and rarely see a vegetable be healthier than we are?



Omega−3 fatty acids are a group of fatty acids with several members of the group essential for human health, and incredibly important for your body and brain.


Omega−3 fatty acids are a group of polyunsaturated fats. All fatty acids are chains of carbon, hydrogen and oxygen atoms. Fatty acids are made up of a long-chain carbon skeleton (chains consisting only of carbon and hydrogen atoms) ending in a so-called carboxyl (-COOH) group. Polyunsaturated fatty acids are fatty acids that contain more than one double bond in their backbone (poly = many).

The name of omega-3 refers to the position of the final double bond in the chemical structure. In these fatty acids, the first double bond is between the third and fourth carbon atoms from the tail end of the chain.

The human body is unable to produce omega-3 fatty acids on its own as we lack the enzymes necessary to insert a double bond at the omega-3 position of a fatty acid. We only can make intragroup conversions (creating one from another), thus we must get omega-3s from our daily diet. This is why they are termed essential fatty acids.

In terms of human health and nutrition, the three most important types of omega-3 fatty acids are:

  • ALA (alpha-linolenic acid),
  • EPA (eicosapentaenoic acid),
  • DHA (docosahexaenoic acid).

They are all needed for optimal functioning of the metabolism, and have important roles in all sorts of bodily processes. These include a vital structural role in cell membranes, and serving as precursors to many other substances that play a fundamental role in a number of physiological functions, including the regulation of inflammation, immunity, blood pressure and platelet aggregation, among others.



The potential health benefits of omega-3 fatty acids have been the focus of much research in the past two decades. Let’s look at some of this research.

  • Cardiovascular health. A number of studies reported the benefits of dietary consumption of omega-3 fatty acids in cardiovascular health.15-29 According to the European Food and Safety Authority DHA and EPA contribute to normal functioning of the heart, to the maintenance of normal blood pressure, and maintenance of triglyceride levels. ALA, meanwhile, contributes to the maintenance of normal blood cholesterol levels.15-17
  • Brain health and mental functioning. According to the European Food and Safety Authority, DHA contributes to the maintenance of normal brain function.17 Over half of the brain’s dry weight is comprised of lipids, and it is especially rich in omega-3 fatty acids. Maintaining optimal lipid composition in the brain, and especially DHA levels, is critical for mental and cognitive health, and for healthy aging of the adult brain. Deficits in EPA and DHA have been associated with neurological disorders, with particular neurodegenerative conditions, and is not conducive to optimal cognitive functioning. 17, 30-33, 110-116
  • Eye health. DHA contributes to maintenance of normal vision. 17 Inadequate intake and decreased blood levels of omega-3 fatty acids have been found to be associated with eye disease. 34-36
  • Joint health. Omega-3 fatty acids are involved in the modulation of inflammatory processes. They have been used to relieve joint pain and inflammation associated with joint diseases, such as rheumatoid arthritis, osteoarthritis. 69-84

In an extensive analysis researchers from the University of Toronto concluded that omega-3 supplementation reduces patient reported joint pain, minutes of morning stiffness, number of painful and/or tender joints, and the necessary amount of NSAID (nonsteroidal anti-inflammatory drug) taken by subjects.69

  • Bone health. Recent research highlighted the role of omega-3s in inflammatory regulation of the bone remodeling process. The research suggests a relationship between higher omega-3 fatty acid levels and better bone mineral density in older adults.133-135
  • Weight loss. Omega-3 fatty acid supplementations can be an integral part of weight-loss interventions. In a clinical trial, the inclusion of fish oil supplements as part of an energy-restricted diet of young men resulted in approximately 40% more weight loss after 4 weeks than did a similar diet without supplements of marine origin. 57

Omega 3’s are involved in the modulation of the inflammatory process that may contribute to many disease states, including type 2 diabetes, insulin resistance, and obesity. 37- 57

  • Muscle mass. Omega-3 fatty acid supplementation may help in your muscle building efforts. Studies demonstrate that fish oil supplementation not only stimulates muscle protein synthesis in older adults, but can alleviate the muscle protein anabolic resistance associated with old age. In addition, it can actually boost the anabolic stimuli from substrates (e.g. amino acids or proteins) or hormones (e.g. insulin) in healthy muscles in young and middle-aged adults. 86, 87, 88
  • Healthy sleep patterns. DHA is involved in the production of melatonin (the hormone that regulates sleep and wakefulness) and, as such, low levels of DHA can interfere with sleep. In studies, higher consumption of fish-derived omega-3 fatty acids have been found to improve sleep continuity and duration. 118-125
  • Healthy skin and hair. Deficits of Omega 3’s have been shown to affect skin function and appearance, and lead to skin abnormalities. Typical maladies include lesions, dryness, scaliness, redness, increased sensitivity and other manifestations of inflammation. Atopic dermatitis (atopic eczema), psoriasis and acne have also been found to be linked to essential fatty acid deficits. Studies found that supplemental omega-3 shows promise as a safe adjunctive treatment for many skin disorders, including atopic dermatitis, psoriasis and acne vulgaris. In addition, omega-3 fatty acids may improve the skin’s appearance, and mitigate both chronological and sun-damage induced signs of aging, including wrinkle formation, dryness and thinning of the skin. 89-103
  • Adequate consumption of omega-3 fatty acids, and especially DHA is vitally important during pregnancy as they are necessary for the development and maturation of fetal brain. Epidemiological studies have shown that balanced fatty acid consumption may affect pregnancy outcome and the neurodevelopment of the fetus. 59,-61 High quality trials have found evidence for a positive effect of omega-3 supplementation during pregnancy. A comprehensive review published in The British Journal of Nutrition found a 31% reduction of the risk of preterm births in all pregnancies and 61% reduction in high-risk births, when mothers supplemented with omega-3 fatty acids. 62-68

In addition, a systematic review of maternal DHA supplementation indicated that DHA supported mental development and longer-term cognitive functioning of the child. 63 Researchers found that DHA supplementation by pregnant women conferred a cognitive benefit to their child on intelligence tests at 4 or 5 years of age. 64-67



ALA is mainly found in plants. Flaxseeds, walnuts, chia seeds and their oils are among the richest dietary sources of ALA, while DHA and EPA are mainly found in animals, especially marine foods and algae.

It is important to note that, strictly speaking, only ALA is considered essential, because the body can use it to form the more important longer-chain omega−3 fatty acids EPA and DHA. But the capacity of this conversion process in the metabolism is considered very low. In addition, it may also be impaired by a number of external and internal factors such as aging, diet (i.e. the ratio/amount of omega-3 and omega-6 fatty acids in the diet, B vitamin adequacy), smoking, chronic alcohol consumption, air pollution and sex (conversion of ALA to EPA is greater in women than men, which may be due to a regulatory effect of estrogen). 126-132

Due to this low conversion efficiency, it is generally advised to obtain EPA and DHA from additional sources.141

Accordingly, European Food Safety Authority (EFSA) sets a minimum dietary requirement of 250 mg ofdirect EPA and DHA for the maintenance of optimal health, on the top of the AI level for alpha-linolenic acid (ALA) which is defined as the 0.5% of total daily energy (ie: calorie) intake. 1

The main dietary sources of EPA and DHA are cold-water oily fishes, such as salmon, herring, mackerel, anchovies, and sardines. Eating about two servings of fatty fish per week covers the above recommended daily amount. 



Studies show that a major part of the world population does not meet the minimal dietary recommendations for omega-3 fatty acids EPA and DHA.

A review that included 266 individual surveys, representing 113 countries and 82% of the global population, found that only 18.9% of the surveyed population met optimal intake for seafood omega-3 fats (EPA+DHA≥250 mg/day).137

In addition, studies that investigated the blood levels of EPA + DHA -which may be more reliable indicators of deficiency than simple assessments of dietary intake-, found that most countries and regions of the world had levels that are considered low to very low.140



When choosing an omega-3 supplement there are two important things to consider:

  • First, omega-3 supplements are one of the nutritional aids where quality is crucial. Several fish species may contain high levels of contaminants, including methylmercury, polychlorinated biphenyls (PCBs), and dioxins. These compounds, and especially organic mercury compounds are toxic and can cause brain and kidney damage.141
    In general, fish oil based omega-3 supplements are considered safer than direct fish consumption, because contaminants, and especially mercury accumulates in the muscle rather than the fat of fish.
    Despite the fact that independent laboratory analyses found that commercially available omega-3 fatty acid supplements are generally free of methylmercury, PCBs, and dioxins,141 products manufactured under low quality control should be avoided.
  • Secondly, do not mistake total fish oil or total fatty acid content with EPA and DHA EPA and DHA are only specific types of fatty acids, and thus comprise only a part of the total fat content.
    When you chose your products, the main point is not their total fat content, but rather their EPA and DHA content, which are responsible for the beneficial effects.

Choose fish oil, krill oil or algae based supplements from reputable manufacturers that provide high quality, contaminant-free source of long chain omega-3 fatty acids (EPA and DHA). The majority of fish oil products contain a natural level of 30% of EPA and DHA content, meaning that a 1000 mg fish oil capsule consists of 300 mg EPA+DHA. More concentrated formulas are also available, which may contain a higher level of EPA and/or DHA on a gram per gram basis.



The European Food Safety Authority (EFSA) sets an Adequate Intake (AI) level for alpha-linolenic acid (ALA) at 0.5% of total daily energy (ie: calorie) intake, as well as 250 mg of combined EPA and DHA (long-chain omega-3 polyunsaturated fatty acids), as a recommended daily consumption level for the maintenance of optimal health. 1

It is also emphasized that the beneficial effects for disease prevention (i.e. for the maintenance of normal blood pressure, and for the maintenance of normal triglyceride levels) is obtained with a daily intake of 2 to 3 grams of EPA and DHA, but no more than 5 grams. 15-17

The World Health Organization recommendations for total omega-3 fatty acid intake can range between 0.5-2% of total daily energy (ie: calorie) intake (with a minimum dietary requirement of ALA at 0.5% of total daily energy intake for adults), while it is also highlighted that direct EPA and DHA have to be a part of a healthy diet in an acceptable macronutrient distribution range from 250mg (as minimum) to 2000mg.142

In short, 250 mg should be a minimum limit for our daily EPA and DHA intake, while the majority of the studies mentioned above combined EPA and DHA supplements in the range of 1-4 grams per days for the beneficial effects.



The EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) concluded that supplemental intake of EPA and DHA upto 5 grams per day, and supplemental intake of EPA alone up to 1.8 grams per day, do not raise safety concerns for adults.144


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