Intake, ingredients and dosage of omega-3 fatty acids

Application

Omega-3 fatty acids fulfill various important functions in the human body. Omega-3 fatty acids support, among other things, the normal function of the brain and eyes, as well as the cardiovascular system. As a component of cell membranes and precursors of various messenger substances, they work in a variety of ways (1).

As essential fatty acids, omega-3 fatty acids must be supplied through food, as the body cannot produce them itself (1,2). To ensure an adequate supply of these valuable nutrients, regular consumption of fish is particularly recommended (3).

Omega-3 fatty acids

Omega-3 fatty acids are a group of essential fatty acids that the human body cannot produce itself (1,2). More specifically, the term omega-3 fatty acids describes four specific fatty acids: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). While ALA is found in many plant foods such as flaxseed and walnuts, EPA and DHA are found primarily in marine sources such as fatty fish and algae (1,2,4):

Eicosapentaenoic acid (EPA) plays a role in many metabolic processes. DHA and so-called eicosanoids are formed from the fatty acid. Eicosanoids are hormone-like substances that act both as neurotransmitters and as immune modulators. They serve the body as central messengers. EPA therefore contributes, among other things, to normal heart function (1).

Docosahexaenoic acid (DHA) , on the other hand, is mainly found in the cell membranes of nerve cells. It is particularly common in the retina of the eye and in the brain. It makes up 40% of the fatty acids found in our brain and 60% of all fatty acids contained in the retina of the eye. DHA therefore contributes primarily to normal brain function and vision (1).

What are omega-3 fatty acids composed of?

Fatty acids are fat-soluble molecules that consist of a carbon chain of varying lengths. The fat in food consists mainly of so-called triglycerides, i.e. three fatty acids connected by a molecule of the alcohol glycerin. Omega-3 fatty acids form a subgroup of polyunsaturated fatty acids . This means that their organic chemical compound contains at least two carbon double bonds. The n in omega-n acids indicates the position of the first double formation of the fatty acid, starting from the omega end. In omega-3 fatty acids, the double bond is in the third position from the end (4).

As essential nutrients, omega-3 fatty acids must be consumed regularly through food. There are both animal and plant foods that contain omega-3 fatty acids. Some plant oils such as linseed and chia oil contain particularly high levels of ALA. Fish and fish oils top the list of animal products. They mainly contain EPA and DHA. Due to this different composition, eating fish cannot simply be replaced by linseed, for example (1,2,3,4).

Fatty fish such as herring, salmon, mackerel, or anchovies are recommended to cover the omega-3 requirement (3).

Omega-3 fatty acids from animal or plant products?

ALA is predominantly found in vegetable oils, legumes and grains. This must first be converted in the body into the two fatty acids DHA and EPA. However, this conversion only takes place to a small extent of less than 10% (5).

Unlike plant products, fish and fish oils already contain DHA and EPA. It is therefore sensible not to base your omega-3 intake exclusively on plant products. However, it is not only the proportion of omega-3 fatty acids that is important, but also the ratio between omega-3 and omega-6 fatty acids (6).

Both omega-6 and omega-3 fatty acids are converted into eicosanoids. They require the same enzyme system. Omega-6 fatty acids are converted into inflammatory eicosanoids, while EPA is converted into anti-inflammatory eicosanoids. It is therefore important to ensure the right ratio between omega-6 and omega-3: it should be around 2:1 to 5:1. However, our modern lifestyle and diet often contribute to a significant excess of omega-6 fatty acids in our bodies. The ratio is then up to 20:1 (4,6).

Vegetable oils such as sunflower and safflower oil in particular contain a high proportion of omega-6 fatty acids. For a balanced diet and a healthy omega-3 balance, care must therefore be taken not to consume too much omega-6 (6).

How should you take omega-3 fatty acids?

The Omega-3 requirement should be met primarily through a balanced diet. This includes plant-based sources such as linseed, but also fatty cold-water fish such as mackerel, herring, or salmon (3). However, eating these fish is becoming increasingly difficult. In addition to overfishing in countless fishing areas, the pollution of the world's oceans plays an important role here. Fatty and large fish in particular tend to store fat-soluble environmental toxins and heavy metals (7). This increasingly relativizes the health benefits of the Omega-3 fatty acids from fresh fish.

Nutritional supplements can be a solution to this problem. High-quality fish oil goes through special filtering processes that ensure that the pollutant content is reduced to a minimum. The choice of fish can also help here: because of their short lifespan, tiny fish such as anchovies accumulate far fewer pollutants than large predatory fish.

Omega-3 fatty acids in the form of dietary supplements are best taken with meals . Long-term use is possible, especially if you don't want to eat fresh fish at all. As a rule, taking them in the morning is recommended; many users feel fitter and more energetic throughout the day. However, it is important to make sure that fish oil capsules are not taken on an empty stomach, but rather during a meal. This significantly increases the bioavailability of the omega-3 fatty acids: by allowing fat to reach the digestive tract before the omega-3 fatty acids are taken, the necessary digestive enzymes and bile acids are already released (4).

Daily dose

Determining an adequate intake of omega-3 fatty acids is not that easy and the recommendations actually vary. The European Food Safety Authority (EFSA) recommends a daily intake of 250 mg EPA and/or DHA as a reference (8). To meet this requirement, the German Nutrition Society recommends at least one meal with fatty fish per week (3).

However, there are other sources that also recommend a higher intake: The Omega-3 Working Group recommends a minimum intake of 300mg, which can even be increased to 1000mg for people with cardiovascular diseases (9).

Overdose

As with all things, the dose makes the poison when it comes to omega-3 fatty acids: excessive intake should always be avoided. But at what point is the dose too high?

The European Food Safety Authority (EFSA) states that an intake of up to 5000 mg of EPA and DHA is considered safe (8). This is twenty times the daily intake they recommend and still five times the daily dose recommended by the Omega-3 Working Group for people with cardiovascular diseases (9). This shows that an overdose is very unlikely with a normal diet and well-considered supplementation. If in doubt, you should follow the manufacturer's recommended dosage and discuss the intake with your doctor if necessary.

Sources

1. Shahidi, F., & Ambigaipalan, P. (2018). Omega-3 Polyunsaturated Fatty Acids and Their Health Benefits . https://doi.org/10.1146/annurev-food-111317
2. German Nutrition Society (DGE). https://www.dge.de/wissenschaft/referenzwerte/fett-essenzielle-fettsaeuren/ (accessed online. December 28, 2023)
3. German Nutrition Society (DGE). https://www.dge.de/gesunde-ernaehrung/dge-ernaehrungsempfehlungen/dge-ernaehrungskreis/fleisch-wurst-fisch-und-eier/ (accessed online: December 28, 2023)
4. Cholewski, M., Tomczykowa, M., & Tomczyk, M. (2018). A Comprehensive Review of Chemistry, Sources and Bioavailability of Omega-3 Fatty Acids. Nutrients , 10 (11). https://doi.org/10.3390/NU10111662
5. Domenichiello, AF, Kitson, AP, & Bazinet, RP (2015). Is docosahexaenoic acid synthesis from α-linolenic acid sufficient to supply the adult brain? Progress in Lipid Research, 59, 54–66. https://doi.org/10.1016/j.plipres.2015.04.002
6. Simopoulos, A. P. (2002). The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomedicine & Pharmacotherapy = Biomedicine & Pharmacotherapy, 56(8), 365–379. https://doi.org/10.1016/s0753-3322(02)00253-6
7. Girolametti, F., Annibaldi, A., Illuminati, S., Carnevali, O., Varola, M., & Truzzi, C. (2023). Determination of Hg and Se in swordfish (Xiphias gladius) from Mediterranean Sea: Implications for nutritional recommendations during pregnancy and childhood. Marine Pollution Bulletin, 197, 115741. https://doi.org/10.1016/j.marpolbul.2023.115741
8. European food safety authority (EFSA). Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). 2012, EFSA Journal 2012;10(7):2815. https://doi.org/10.2903/j.efsa.2012.2815
9. Omega-3 Working Group e. V.https://ak-omega-3.de/omega-3-fettsaeuren/wieviel-omega-3-fettsaeuren-braucht-der-mensch/ (accessed online: December 28, 2023)