Omega-3 fatty acids are essential for us humans. We have to ingest them through food – such as vegetable oils and sea fish – in order to maintain the important functions of our organism. But do the polyunsaturated fatty acids actually have a preventive effect against cardiovascular diseases? Or is an increased intake of fats even harmful to health? Below we answer all questions about omega-3 fatty acids.
What Are Omega-3 Fatty Acids?
Omega-3 fatty acids are essential fatty acids. Essential means that we have to ingest them with food because the human body cannot make them ourselves.
Omega-3 fatty acids are among the polyunsaturated fatty acids. This means that there are several double bonds in their molecular structures. This is the difference to saturated fatty acids, which have no double bonds.
The omega-3 fatty acids are mainly contained in vegetable oils and fatty sea fish.
Omega-3 and Omega-6 Fatty Acids
Omega-3 fatty acids can be divided into different types of fatty acids. The relevant acids are:
- α-linolenic acid (alpha-linolenic acid, ALA)
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
Our organism can form EPA and DHA from α-linolenic acid, which is why only this can be described as actually essential for adults.
How effective this synthesis is depends on the intake of omega-6 fatty acids. These are also unsaturated fatty acids that are essential for life. However, there is a complicated relationship between omega-3 and omega-6 fatty acids.
In the human body, both types of fatty acids are processed in the same enzyme system. If there is a mismatch between the different types, malfunctions can occur. A 5: 1 ratio of omega-6 to omega-3 fatty acids is ideal. However, we tend to ingest too much omega-6.
What is Omega-3 Good For?
The human body needs omega-3 fatty acids to build cell membranes. These should be adaptable and – for the right materials – permeable. Some omega-3 fatty acids are anti-inflammatory, act as precursors to hormones, or contribute to normal brain function and maintenance of eyesight.
Research also shows that omega-3 fatty acids are most likely to have a positive effect on triglyceride levels in the blood. It is a certain type of nutritional fat. The triglyceride value belongs to the complex, which is also referred to as “cholesterol values”. These are three individual values.
In addition to the trigylceride level, this includes the HDL and LDL values. Put simply, HDL is “good” cholesterol and LDL is “bad”. It is therefore important that there is sufficient HDL cholesterol in the body in relation to LDL. Unfavorable cholesterol levels are considered a risk factor for the development of arteriosclerosis and cardiovascular diseases.
Omega-3 Fatty Acids: Increased Intake Is Not Advisable
For a long time, omega-3 fatty acids were a real miracle cure that should help against just about every disease. A positive influence on depression, the function of the kidneys in diabetics and an effect against pain have been discussed. Above all, however, the fats were used to protect against serious cardiovascular diseases such as a heart attack or stroke.
The so-called Cochrane Review from 2018 brought disillusionment to the latter aspect.1 This review is a meta-study for which 79 randomized studies with a total of over 110,000 participants were evaluated.
The question was: Does an increased intake of omega-3 fatty acids have advantages for heart health? The answer was clear: no. A minimal preventive effect against cardiac arrhythmia was found, but due to the low effect it can be neglected according to the scientists.
And not only that: An excessive intake of omega-3 fatty acids can even harm us. High doses can increase the risk of bleeding, nausea and vomiting. The preventive effect against cardiac arrhythmia is then eliminated, rather such disorders can only be triggered and the LDL concentration increased. Diabetics can have problems with blood sugar and the immune system may be weakened.
For these reasons, the Federal Office for Risk Assessment has recommended for many years that a recommended upper limit for daily omega-3 intake should be set.
How healthy Are Omega-3 Fatty Acids?
However, these study results do not prove that omega-3 fatty acids are unhealthy and we should refrain from consuming them. The opposite is the case. Because – we remember – omega-3 fatty acids are essential, so essential.
The research presented has only shown that an increased intake beyond the daily need will most likely have no or little benefit for heart health. This does not change the fact that we have to ingest omega-3 fatty acids daily with food or – if we fail to do so – with a dietary supplement.
What omega-3 fatty acids are also good for has not yet been finally clarified. Studies are currently underway to determine whether they can actually help treat depression, protect against dementia, or have other health effects.
Who Needs Omega 3 – and How Much?
It is recommended that the daily intake of omega-3 fatty acids should account for 0.5 percent of the calories.3 For an adult with a daily consumption of 2,400 kilocalories (kcal), this corresponds to 1.3 g omega-3 fatty acids per day and thus about a tablespoon of rapeseed oil.
The need is slightly increased during pregnancy, because the fatty acids are important for the neurological development of the child and his eyesight. If you are pregnant and want to know if you need an omega-3 supplement such as fish oil capsules or fortified foods, the best thing to do is to discuss this with your doctor.
Infants cannot yet produce EPA and DHA from α-linolenic acid. So you also have to include EPA and DHA. As a rule, adequate supply for infants through breast milk is provided.
Omega-3 Deficiency: Who is At Risk?
A lack of omega-3 is very rare. The symptoms are rather non-specific, so they do not clearly indicate an omega-3 deficiency. Possible signs include:
- Problems with eyesight and eyes
- Difficulty concentrating
Such a deficiency is diagnosed using a blood test. If a visit to the doctor is out of the question, you can use a test kit for at home. Here you take a small blood sample yourself and send it to a laboratory, where it is evaluated.
People who eat a balanced and healthy diet do not need an omega-3 supplement. Your needs are covered by the food you eat. If fish are not used, for example as part of a vegetarian or vegan diet, compensation may have to be provided.
Dietary Supplements: What Should Be Considered?
Due to their double bonds, omega-3 fatty acids are very reactive and therefore oxidize quickly, which means that they undergo chemical reactions with oxygen. To prevent this, most supplements with omega-3 antioxidants are added.
Capsules containing omega-3 with vitamin D or coenzyme Q10 are also available. If dietary supplements that combine omega-3 with vitamins are taken, caution is also required here with regard to the daily requirement: If the recommended daily maximum intake of certain vitamins is significantly exceeded, serious health risks sometimes arise.
If you want to buy omega-3 capsules, you should also take a look at the list of ingredients: fish oil capsules are often obtained from krill. However, whales, seals and penguins, for example, are dependent – either directly or indirectly – on sufficient krill stocks. Omega-3 supplements made from microalgae are therefore more environmentally friendly and also suitable for vegans.
Where is the Most Omega-3?
Foods with omega-3 fatty acids are, on the one hand, high-fat sea fish such as salmon and tuna, and on the other hand vegetable oils such as linseed oil, walnut oil and rapeseed oil. Nuts, avocados and green leafy vegetables are also suitable omega-3 suppliers.
Olive oil also contains omega-3 fatty acids, but the ratio to omega-6 is rather unfavorable.
In order to optimize the utilization of omega-3 fatty acids from vegetable oils or fish, it is advisable to pay attention to the correct ratio to the consumption of foods with omega-6 fatty acids. A lot of omega-6 is found in safflower and sunflower oil, for example.
It is generally recommended not to take omega-3 capsules without medical advice. Instead, you should rather eat a portion of (high-fat) sea fish once or twice a week, prefer to use vegetable oils rich in omega-3 and reduce the consumption of meat and sausages if possible.