Status: 04.03.2024 21:00

Omega-3 fatty acids from fish, algae, nuts and seeds are said to have almost miraculous effects on health. Studies underline their benefits, but also show dangers.

by Britta Probol

Salmon, herring, mackerel and anchovies in particular, but also linseed, walnuts, hemp and certain oils are known for their high content of so-called omega-3 fatty acids. Recently, we have been hearing more and more about so-called “algae oils” or “omega-3 oils”. What is the truth? And what is the so-called omega balance all about?

Effects of omega-3 fatty acids in the body

In fact, omega-3 fatty acids are of great importance for human metabolism. They are a building block of our cell membranes and keep the cell membranes supple. How well our nerve cells work depends on the proportion of healthy fatty acids in the cell membranes. Omega-3 fatty acids are particularly important for the brain development of the child during pregnancy and can apparently help They are also needed for the production of various tissue hormones (the body’s own messenger substances). Omega-3 fatty acids play a role in blood pressure regulation and kidney function, and they also have an anti-coagulant effect. Studies have also shown that omega-3 fatty acids strengthen the immune system and reduce inflammatory processes, including in acne. Inflammation plays a role in many diseases – not least in arteriosclerosis and the resulting cardiovascular diseases.

ALA, DHA, EPA: Vital building blocks in the organism

Omega-3 is one of the so-called polyunsaturated fatty acids. Three of them are particularly important for the human body:

  • On the one hand, the plant-based omega-3 fatty acid Alpha-linolenic acid (ALA). It is essential. This means that our body cannot produce this fatty acid itself and therefore relies on us consuming it through food. Alpha-linolenic acid is found in plant-based foods, particularly in flaxseed and flaxseed oil, as well as in walnuts and walnut oil, hemp and hemp oil, and rapeseed oil.
  • On the other hand, the two particularly metabolically active omega-3 fatty acids Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA)Our body can produce them itself from ALA (i.e. from the plant-based omega-3 fatty acid), but only in very small quantities. In addition, the conversion is blocked by high omega-6 concentrations. EPA and DHA are particularly abundant in fatty cold-water sea fish: salmon, herring, mackerel, anchovy. EPA and DHA are also found in higher concentrations in tiny crustaceans from cold waters (krill) and certain microalgae (for example spirulina, chlorella or schizochytrium algae). These are used alongside fish oil to produce omega-3-containing food supplements.

Treat sensitive Omega-3 vegetable oils properly

Linseed oil and linseed on a wooden table. © Photo: cut
Flaxseed and linseed oil contain particularly high levels of ALA.

The main plant source of omega-3 fatty acids is linseed oil. A hundred years ago, it was almost the only oil in Germany. Then the linseed plant, which is also known as flax (a source of linen), was almost forgotten for a long time. Among other things, cooking oil is pressed from the seeds of the linseed. Linseed oil has a slightly nutty taste and goes well with salads or quark with boiled potatoes. The oil gives cream cheese a special flavor.

Due to its particularly high content of the valuable omega-3 fatty acid ALA (50 to 60 percent), linseed oil is very sensitive to light and easily goes rancid. When purchasing, you should pay attention to high-quality production – the criteria: organic, cold-pressed or pressed under exclusion of light, heat and oxygen, for example using the “Omega-safe” or “Oxyguard” process. The oil should be stored in a dark and airtight place, used fresh and consumed within three weeks of opening, otherwise the positive health effects are lost. Important: linseed oil should never be heated.

Hemp oil contains about 17 percent of the omega-3 fatty acid ALA and also belongs in cold dishes. Walnut oil and high-quality rapeseed oil still contain around ten percent ALA – these oils are more heat-resistant and can be added to hot dishes, but they should not be used for frying.

Farmed salmon: higher proportion of omega-6

A trout, two salmon steaks and a halved lemon lie on a piece of parchment paper. © fotolia Photo: George Dolgikh
Fatty fish such as salmon contains large amounts of unsaturated fatty acids.

Salmon is particularly popular among the fish rich in omega-3. Today, it mainly comes from large breeding farms. There, the predatory fish is fed more plant-based feed, which contains a higher proportion of omega-6 than its natural animal diet. There are fears that this will worsen the ratio of omega-6 to omega-3 in salmon. However, samples show that the ratio can still be good even in farmed salmon.

The “Omega balance” is extremely important

In order for omega-3 fatty acids to work well in the body, our diet must not contain too many omega-6 fatty acids. Omega-6 fatty acids are found in sunflower or safflower oil, for example, and in processed foods. Why is the omega balance so important? Because our metabolism processes omega-6 and omega-3 fatty acids using one and the same enzyme. If all enzymes are “occupied” with omega-6 fatty acids, the body cannot absorb omega-3. Today, our food contains on average 10 to 20 times more omega-6 than omega-3 fatty acids. The ratio of omega-6 to omega-3 should actually be between 1:1 and 5:1.

Blood test determines the Omega Index

Thus, the sufficient supply of omega-3 fatty acids depends not only on how much fish or linseed oil you eat, but also on the “overall balance” of the fats you consume. The actual metabolism can vary from person to person. A special blood test was developed to determine how much EPA and DHA actually reach the blood. It takes advantage of the fact that fatty acids attach themselves to red blood cells and can be measured there. A so-called omega-3 index of 8 to 11 percent is considered optimal. However, determining this laboratory value is not routine and is not covered by health insurance companies.

Omega-3 capsules from the pharmacy and dietary supplements

Due to the numerous health-promoting effects of omega-3 fatty acids, they are now successfully sold as dietary supplements. While prescription drugs from the pharmacy consistently contain 460 mg EPA and 380 mg DHA in 1,000 mg of omega-3 fatty acids, the amounts in over-the-counter dietary supplements vary considerably. The consumer advice center points out that manufacturers of food supplements only have to state the total content of omega-3 fatty acids and not how much ALA, EPA or DHA is contained in each individual product.

Further information

Tablets of different shapes and colors © Photo: motorlka

Dietary supplements can lead to an overdose of vitamins and minerals – with dangerous consequences. more

Foods with Omega-3 added

The food industry has discovered omega-3 fatty acids as a marketing factor and now adds algae extracts (EPA/DHA) to many foods, from soy milk to cooking oils (“omega-3 oil”) to the breading of fish fingers. This increases the price of such products, but it does not turn an unhealthy food into a healthy one. For example, “omega oils” are on the market that consist mainly of cheap sunflower oil, thus providing a lot of omega-6 – and it is often difficult to estimate the dosage of the added EPA/DHA.

Algae oil as a dietary supplement

A plate with nuts, seeds, oils and various fish specialties. © NDR
Only a few foods contain omega-3 fatty acids.

So-called algae oils are relatively new on the market. These are usually mixtures of various cooking oils (such as linseed, olive or MCT oil) with very high doses of EPA and DHA added from microalgae. Algae oil can also be bought in capsule form. The oil is extracted from microalgae – not from the large algae used for sushi or other Japanese specialties. Algae oil is almost iodine-free. The microalgae grow in nutrient solutions in special breeding facilities, known as aquacultures. The omega-3-rich oil is extracted from the algae biomass using complex processes. Algae oil is a purely plant-based alternative for people who do not want to eat fish or fish oil.

Side effects of Omega-3 supplements

As with everything, the same applies to omega-3 fatty acids: Do not overdo it – where there are effects, there are also side effects. In 2009, the Federal Institute for Risk Assessment recommended Opinion for healthy consumers a maximum amount of 1.5 grams of EPA/DHA per day on average. The European Food Safety Authority EFSA, on the other hand, saw in a In a 2012 statement, the intake of up to 5 grams of EPA and DHA (in combination) is considered safe for adults. This assessment does not apply to people with pre-existing medical conditions.

Omega-3 fatty acids may apparently increase the risk of atrial fibrillation

A US study that Framingham Heart Study, showed that people with high omega-3 levels in their blood have a lower risk of cardiovascular disease. 2021 has a large Meta-analysis, on the other hand, shows that more than 1 gram of omega-3 supplementation of marine origin (such as algae oil or fish oil capsules) can apparently lead to cardiac arrhythmias: In people with an existing or impending heart disease, taking omega-3 supplements can therefore Increase the risk of atrial fibrillation. However, it has been criticized that important data such as the Omega-3 index of those affected were not available.

Discuss daily requirements and dosage with doctor

Those who take Omega-3 in high doses as a dietary supplement may experience an increased tendency to bleed, which can manifest itself in nosebleeds, for example. This is even more true for people who are already taking medication to prevent blood clotting. In any case, it is a good idea to speak to your doctor or pharmacist before buying dietary supplements.

Last but not least, you can significantly improve your omega balance by eating fewer omega-6 fatty acids (e.g. less sunflower oil, safflower oil, ready-made products) and instead eating more plant-based omega-3 sources such as nuts and linseed oil – and occasionally a good piece of fish.

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The Nutrition Docs | 04.03.2024 | 9:00 p.m.