In this article, we'll take a closer look at omega-3 fatty acids. We'll explain their definition and scientific background, examine the different types and explain why they are so important for our health.
What is omega-3?
Omega-3 fatty acids are a type of polyunsaturated fat that are vital for the human body. They are considered "essential" fats because our body cannot produce them itself and we must therefore obtain them from our diet.
Scientifically speaking, they consist of long-chain carbon atoms that are linked together by double bonds. The position of these double bonds defines them as omega-3 fatty acids.
There are three main types of omega-3 fatty acids:
- Alpha-linolenic acid (ALA): It is mainly found in plant foods such as flaxseed, hempseed, chia seeds, walnuts and certain oils such as linseed oil and rapeseed oil. ALA is a short-chain fatty acid, which the body can convert into the other two types, but only to a limited extent.
- Eicosapentaenoic acid (EPA): EPA is a long-chain fatty acid found mainly in fatty fish, algae and seafood . It plays an important role in reducing inflammation in the body and is also important for heart health.
- Docosahexaenoic acid (DHA): DHA is the longest of the three fatty acids and is also found in oily fish, seaweed and seafood. DHA is crucial for brain health and visual function.
In a nutshell. ALA is the shortest form of omega-3 fatty acids. EPA is formed by adding further molecules and double bonds. If you extend EPA further, you get DHA.
Why is omega-3 so important for humans
Fatty acids are important for our health for several reasons.
Health benefits of omega-3:
- Heart health: Omega-3s can help reduce the risk of heart disease. They also lower triglyceride levels in the blood, lower blood pressure, reduce the risk of blood clots and improve the health of blood vessels.
- Brain health: DHA is an important component of the brain and the retina of the eye. It plays a crucial role in the development of the infant brain. In adults, an adequate intake of DHA can help to reduce the risk of dementia and mental decline.
- Anti-inflammatory: Omega-3 fatty acids have strong anti-inflammatory properties. They can help to alleviate the symptoms of chronic inflammatory diseases such as rheumatoid arthritis and Crohn's disease.
- Joint health: Omega-3 fatty acids are thought to help relieve the symptoms of arthritis by reducing stiffness and joint pain.
- Improving mood: Some studies have shown that omega-3 fatty acids can help alleviate the symptoms of mood disorders such as depression and anxiety.
The role of omega-3 fatty acids in cell function and immune defense
Omega-3 fatty acids play an important role in numerous cell functions. They are a component of cell membranes and influence their function, including the transmission of signals between cells.
In addition, they play an important role in immune defense. They can modulate the immune response and attenuate inflammatory reactions, which is particularly important in autoimmune diseases and chronic inflammation . Exactly how omega-3 fatty acids affect the immune system is not yet fully understood, however.
The effect in the human body
Omega-3 fatty acids are essential for several important functions in the body. They make a significant contribution to our general well-being and health.
- Hormone production: Omega-3 fatty acids play a crucial role in the production of local hormones known as eicosanoids. These are z.B. involved in blood clotting.
- Regulation of blood lipids: They help to regulate the amounts of cholesterol and triglycerides in the blood.
- Cell metabolism and cell membrane structure: Omega-3 fatty acids are fundamental components of cell metabolism and contribute to the structure of the cell membrane.
- Preventing chronic inflammation: They help to prevent chronic inflammatory processes in the body and can influence inflammaging .
- Skin and hair care: Omega-3 fatty acids provide skin and hair with moisture and elasticity.
Promote the conversion to long-chain omega-3 fatty acids
Plant sources of omega-3 fatty acids, such as linseed, walnut and hemp oil, contain short-chain alpha-linolenic acid (ALA). Although ALA has health-promoting properties, it is also important to consume long-chain omega-3 fatty acids , as many of the health benefits can be attributed to these forms.
The human body can convert ALA into the long-chain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, the efficiency of this conversion varies from person to person. In particular, a high intake of omega-6 fatty acids, such as those found in sunflower and corn oil, can inhibit the conversion. This is because omega-3 and omega-6 fatty acids require the same enzymes for their metabolization, with the former often being at a disadvantage.
To increase the conversion rate, it may therefore be helpful to reduce the consumption of omega-6-rich oils. However, there are also other factors that can influence the conversion rate.
Sources of omega-3 fatty acids
Omega-3 fatty acids are found in a variety of foods, both animal and plant-based
Animal sources
- Fish: Oily marine fish such as salmon, mackerel and herring are particularly rich in EPA and DHA. Freshwater fish such as trout and carp also provide large amounts of omega-3.
- Seafood: In addition to fish, other seafood such as crabs and mussels also contain omega-3 fatty acids, albeit in smaller quantities.
Pflanzliche Quellen
- Flaxseed oil and flaxseed: They are an excellent source of ALA. Linseed oil contains around 53 grams of omega-3 fatty acids per 100 grams, while linseed contains around 20 grams per 100 grams.
- Chia seeds: With 19 grams of omega-3 fatty acids per 100 grams, chia seeds are also an excellent plant-based source.
- Hemp oil: It contains about 18 grams of omega-3 fatty acids per 100 grams.
- Walnut oil and walnuts: They are also rich in ALA.
- Other seeds and nuts: In addition to flax and chia seeds, other seeds and nuts such as hemp seeds and walnuts are also good sources of ALA.
- Various vegetables: Some vegetables, including spinach, Brussels sprouts and avocado, also contain significant amounts of omega-3 fatty acids.
Omega-3 and dietary supplements
Taking omega-3 supplements can be useful in certain situations, especially when it is difficult to obtain sufficient amounts of omega-3 fatty acids from the diet. In Germany, around 80% of people do not consume enough of these important fatty acids in their diet.
Possible reasons for supplementation
- Diabetes: In diabetes, taking in combination with vitamin E and other antioxidants (e.g. astaxanthin, OPCs) may be beneficial.
- Vegan diet: Most plant sources contain the short-chain alpha-linolenic acid (ALA). Although this also has some health benefits, most studies have been carried out with eicosapentaenoic acid (EPA). This can also be taken vegan as algae oil.
- Omega 3 index: The omega 3 index can be determined before supplementation. This measures the concentration of EPA and DHA in the red blood cells. Experts such as Dr. Peter Attia advocate keeping the omega 3 index between 8 and 12%. If your index is below this, supplementation could be an option.
Tips for choosing a good omega-3 supplement
- Quality: Pay attention to the quality of the product. It should be pure and free from impurities (especially heavy metals).
- Dosage: The dosage should be tailored to your individual needs. As a rule, a daily dose of around 250-500 mg EPA and DHA is recommended for healthy adults. If you read the studies more closely, most of the health benefits came from a higher dose of EPA. Depending on the study, this was between 1000 and 2000mg. Higher-dose preparations could therefore be beneficial here.
- Dosage form: Omega-3 fatty acids are available in various dosage forms, including fish oil, krill oil and algae oil. Each form has its own advantages and disadvantages.
- Additional ingredients: Some supplements contain additional ingredients such as vitamin E or other antioxidants that can enhance the effect.
- Ester form or natural: In some preparations, the fatty acids are offered as ethyl esters. These must be consumed with food, otherwise they are not absorbed. Fish oil In contrast, omega-3 fatty acids can be absorbed independently of the meal.
Are there important things to consider when taking omega-3 supplements?
The use of products containing omega-3 fatty acids requires careful consideration. In the product labeling only the total content of omega-3 fatty acids per daily dose must be stated, whereby no differentiation must be made between ALA, EPA and DHA. This makes it difficult to compare food supplements. Unless the product is explicitly advertised as "contains DHA" - in which case the DHA content must be stated in the nutritional table.
The intake of food supplements can cause side effects and interactions, even if these do not have to be stated, unlike with medicinal products. Products with up to 5 g EPA and DHA (taken together) or 1.8 g EPA (individually) per day were assessed as safe for adults by the European Food Safety Authority in 2012. For a dosage of 2 g per day or more, a warning is required that the amount of 5 g per day must not be exceeded. However, the available data were found to be insufficient to establish a maximum allowable intake level of omega-3 fatty acids (DHA, EPA, DPA, individually or combined) for specific population groups.
Higher doses may thin the blood, increase bleeding time and increase the risk of bleeding. Other possible side effects include nausea and vomiting. In diabetics, it can make blood sugar control more difficult and impair the immune system, which can lead to increased susceptibility to infections, especially in older people. In the case of an existing infection, additional omega-3 fatty acids should therefore only be given after consultation with a doctor.
Increased LDL due to supplementation
In some studies, taking DHA alone or in combination with EPA led to an increased LDL cholesterol level, which is particularly problematic in certain lipid metabolism disorders. What does this mean? LDL should actually be as low as possible for the health of our blood vessels?
The question is not quite that simple to answer, but there are several reasons why DHA and EPA have led to increased LDL in some studies. Firstly, it seems to be due to the dosage. In some studies, very high amounts of up to 6g daily were given. Secondly, the omega 3 fatty acids do not increase the amount of LDL produced, but appear to affect the LDL receptor so that less LDL can be taken up from the blood into the cell. And thirdly, there is the question of whether this is a bias, as these results occurred in patients who already had very high triglyceride levels and LDL levels anyway.
Particular caution is required when taking medication at the same time. For example, the use of high-dose omega-3 fatty acid products can increase the effect of anticoagulant drugs such as acetylsalicylic acid (ASA) .
Can omega-3 fatty acids be harmful?
Previous research suggested limited cardiovascular benefits of omega-3 fatty acids. These results led to the approval of drugs containing omega-3 fatty acids in a daily dose of 1 gram for secondary prevention after a heart attack. However, a review of these data by the Committee for Medicinal Products for Human Use of the European Medicines Agency (EMA) has concluded that a daily dose of 1 gram of DHA and EPA is not sufficient to protect heart attack patients from further cardiovascular complications .
Recent research has shown that DHA and EPA may increase the risk of atrial fibrillation, a type of cardiac arrhythmia, in people with existing heart disease or related risk factors, depending on the dose. The risk was highest at the highest dose tested in the studies of 4 grams per day. For this reason, the Federal Institute for Risk Assessment advises people with existing or impending heart disease in particular to only take omega-3 fatty acid preparations, such as dietary supplements, after consulting a doctor, especially if they are to be taken over a longer period of time.
Omega 3 and heart health - partly contradictory study results
Omega 3 fatty acids have been tested in many different studies for their health benefits. Two of the largest studies are the REDUCE-IT and the STRENGTH study. While the former showed a risk reduction of 25% for cardiovascular events , the STRENGTH study was unable to confirm this. Instead, it found that excessive concentrations of omega-3 fatty acids increase the risk of atrial fibrillation. So what is true now?
The question is also not so easy to answer. The studies are all structured differently, and the dosages, patient population, duration and outcome are defined differently. If you look at the meta-analyses (i.e. the summary of many large studies), you can recognize a trend:
Omega 3 fatty acids can certainly improve heart health!
With the help of the Omega 3 Index you can determine much more precisely who can benefit from supplements. However, as the majority of the population consumes few omega-3 fatty acids, it can be assumed that most people would benefit from supplementation. Caution is advised with high dosages and pre-existing heart conditions. Especially in the case of known atrial fibrillation, it is better to consult your trusted doctor again.
