What are Omega-3 fatty acids?
You have surely already heard that there are 'good' and 'bad' fats. Fats which, on the one hand, can cause illness in our affluent society – on the other hand, other fats which are vital for our organism. Few people are aware of the fact that, within the second group of good fats, there are also those who can act as true health-bringers. The latter undoubtedly include the omega-3 fatty acids, which affect important metabolic functions in the human body and, therefore, can aid both the prevention and treatment of several diseases, such as cancer, cardiovascular diseases, Alzheimer’s, arthritis depression and asthma.
According to a study by Professor Michael Crawford of the Institute of Brain Chemistry,omega-3 fatty acids in the womb affect the eyesight and intelligence of the embryo and their intake by the expectant mother can still determine whether the child, even in adulthood, will be prone to conditions such as cardiovascular disease. Omega-3 fatty acids are therefore a natural substance that can significantly influence our life from its very beginning and protect against the number one cause of death (cardiovascular degeneration). According to numerous studies, just 30 g of fish per day can reduce the risk of a fatal heart attack or sudden cardiac death by half. This is already guaranteed with two to three fish meals per week. Furthermore, recent study results indicate that omega-3 fatty acids have the immensely important, unique property of slowing telomere shortening on our chromosomes.
The telomeres act as 'protective caps' for our chromosomes, protecting our cells from ageing. Telomere length is considered by age researchers to be the unerring measure of biological ageing and the ability of omega-3 fatty acids to protect against telomere shortening is considered a clear indication that omega-3 fatty acids help our cells, and therefore us, remain young and prolong our life.
Omega-3 fatty acids: the name
Omega-3 fatty acids belong to the group of unsaturated fatty acids and, with 18 or more carbon atoms, are long-chain fatty acids. The first part of the name 'Omega' comes from the last letter of the Greek alphabet and stands for the last carbon atom within the fatty acid chain at the methyl end. The first double bond at this end is located at the third carbon atom, which is the reason for the number 3 within the term 'omega-3 fatty acids'.
Good and bad fats
The 'good' fats are also called 'essential fatty acids', which are the fatty acids that are necessary for life, fatty acids that the organism cannot synthesise from other nutrients (such as fats, amino acids or water), therefore they have to be obtained solely through food. From a chemical point of view, all those fatty acids that contain at least one double bond distally (away from the carboxy group) from the 9th carbon atom are essential for humans.
Specifically, these are two fatty acids, namely omega-6 fatty acid (also called linoleic acid) and omega-3 fatty acid (linolenic acid). The essential fatty acids are polyunsaturated fatty acids. The body cannot make some of these polyunsaturated fatty acids with double bonds at specific positions itself.
From these two essential, vital fatty acids, the body produces other, very important fatty acids and derived products, including arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid.
While we do not particularly have to worry about the supply of omega-6 fatty acids, as they are abundant in our diet, omega-3 fatty acids pose a particular challenge because they are rare in the modern diet we are accustomed to. If our original diet was previously balanced in terms of omega fatty acids, today it is anything but balanced.
According to the 2004 Nutrition Report of the German Nutrition Society, men consume only 250 mg EPA/DHA per day on average, women only 150 mg EPA/DHA (see below for details). The optimal ratio of omega-6 fatty acids to omega-3 fatty acids would be between 2:1 and 4:1. In fact, today's ratio is up to 20:1, which is harmful to our health and needs to change.
Among the most important omega-3 fatty acids are
Alpha-linolenic acid (ALA): Alpha-linolenic acid (ALA) is triple-saturated and occurs in linseed oil, rapeseed oil and walnut oil.
Eicosapentaenoic acid (EPA): Eicosapentaenoic acid (EPA) is quintuple-unsaturated and comes from the fat of cold-water fish, such as mackerel, herring or salmon.
Docosahexaenoic acid (DHA): Docosahexaenoic acid (DHA) is a sextuple-unsaturated fatty acid from fish oils and some algae.
As omega-3 fatty acids are found mainly in oily cold-water fish, such as herring and mackerel, and in vegetable oils, such as linseed oil, rapeseed oil and soybean oil, these foods should be given adequate consideration within an individual diet to ensure adequate nutrition and physiological balance of the omega fatty acids to each other. The importance of a sufficient supply of omega-3 fatty acids becomes clear when one becomes aware of their functions and tasks, which are important for hormone production, cell metabolism, protein synthesis, the formation of endogenous defence cells and the metabolism of the synovial fluid. Therefore, it is not surprising that omega-3 fatty acids have a great positive effect on our health and can positively affect even chronic diseases such as diabetes, rheumatism and Alzheimer's and can also prevent heart attack, atherosclerosis and even cancer.
On the following pages, you will learn everything worth knowing about omega-3 fatty acids. You will learn more about its occurrence, its preventive and therapeutic effects up to the explicit application for specific diseases or for their prevention, supported by representative studies.
Healthy fats vs. unhealthy fats – a little digression
While it is common, in our affluent society, for dietary fats to be seen as the main culprit for the epidemic-like development of obesity, it is all too often overlooked that dietary fats are indispensable and vital to our health. Fats are vital components of our diet. They provide 9 kcal of energy to the body per gram and are the prerequisite for the absorption of so-called fat-soluble vitamins, which include the vitamins A, D, E and K. As components of cells and building blocks of some hormones, building blocks of the cell membrane and precursors of hormone-like regulatory substances, fats are crucial for metabolic processes and our biochemical balance.
Fats take on some vital functions, including the function of
- Saturation: High-fat diets saturate faster than low-fat diets.
- Insulation: Subcutaneous fat protects the body from cold.
- Protection: The internal organs are protected from mechanical influences by fatty tissue.
- Construction: Fat is involved in building cell membranes.
- Provision of fat-soluble vitamins A, D, E and K.
- Precursor of hormone-like regulatory substances.
Saturated and unsaturated fatty acids
Saturated fatty acids
Fatty acids are loaded with carbon atoms and hydrogen atoms. If all carbon atoms of a fatty acid are saturated with hydrogen atoms, we have a 'saturated fatty acid'.
Saturated fatty acids can increase our cholesterol levels and cause atherosclerotic changes to our blood vessels, so they should only be consumed in moderation.
Saturated fatty acids are mostly of animal origin and occur in:
· hard cheese
· beef tallow
· meat and sausages
· palm kernel fat
· coconut fat
Unsaturated fatty acids
If at least two adjacent carbon atoms are linked by double bonds, we have an 'unsaturated fatty acid'. Again, we distinguish between 'monounsaturated fatty acids' and 'polyunsaturated fatty acids'.
Monounsaturated fatty acids occur in:
- olive oil
- peanut oil
- rapeseed oil
- sesame oil
If there are several of these double bonds, it is an 'polyunsaturated fatty acid'. Some of the polyunsaturated fatty acids are among the essential fatty acids that must be taken in food because they cannot be produced by the body.
Polyunsaturated fatty acids occur in:
- linseed oil
- sunflower oil
- almond oil
- soybean oil
- corn oil
- safflower oil
- hazelnut oil
- pumpkin seed oil
The quantity and the right ratio are crucial!
Maintaining optimal health depends on both the right amount of fat and the correct ratio of different fats.
Recommended fat quantity: Our food consists of the three macronutrients 'fat', 'protein' and 'carbohydrates'. The proportion of fats in relation to the other two macronutrients 'protein' and 'carbohydrates' should be a maximum of 35 %. With 2000 kcal consumed daily, this equates to about 77 g of fat per day.
Recommended ratio of fatty acids to each other: Nutritionists recommend a supply of fats consisting of:
- 1/3 animal fats (milk and milk products, meat and sausage products);
- 1/3 from monounsaturated fatty acids (olive oil, rapeseed oil) and
- 1/3 polyunsaturated acids (salt-water fish, rapeseed oil, linseed oil, walnut oil).
It is recommended to eat two servings of salt-water fish every week; opt for linseed, rapeseed and walnut oil instead of the omega-6 rich sunflower, safflower and corn oil to maintain a healthy ratio of omega-3 fatty acids to omega-6 fatty acids.