What role do fatty acids play in the human body?

Fatty acids fulfill many important tasks:

Energy supplier: Fatty acids are an important source of energy for the body. They provide more than twice as many calories per gram as carbohydrates or proteins, which makes them a concentrated energy reserve [1].

Structural components: Fatty acids are essential components of cell membranes. They contribute to the stability and function of cells by influencing the fluidity and permeability of membranes [2].

Hormone production: Some fatty acids serve as precursors for the production of hormones, in particular eicosanoids such as prostaglandins, leukotrienes and thromboxanes. These hormones regulate various bodily functions such as inflammatory reactions, blood clotting and blood pressure [2].

Vitamin absorption: fatty acids support the absorption of fat-soluble vitamins (A, D, E, K) in the intestine and their transport in the body.

Inflammation regulation: Omega-3 fatty acids, especially EPA and DHA, have anti-inflammatory properties and can reduce the risk of cardiovascular disease [2].

Brain function: Fats are important for brain development and function. They make up a large part of the brain structure and are involved in the transmission of signals between nerve cells [3].

Cholesterol regulation: Unsaturated fats, especially the oleic acid contained in olive oil, can have a positive effect on cholesterol levels. They lower the “bad” LDL cholesterol, while leaving the “good” HDL cholesterol unchanged or even increasing it [2].

Immune function: Certain fatty acids play a role in regulating the immune system and can strengthen the body's defenses.

Gene regulation: Some fatty acids can influence the expression of certain genes and thus regulate various metabolic processes [4].

Heat regulation: fatty tissue, which is made up of fatty acids, serves as an insulator and helps the body to regulate its temperature.

How many fatty acids should I consume daily?

The American Heart Association recommends that no more than 30% of daily energy intake should come from fats. Of this, a maximum of 7% should come from saturated fatty acids, at least 10% from monounsaturated fatty acids and 7-10% from polyunsaturated fatty acids. A daily intake of 0.5% of total energy is recommended for omega-3 fatty acids. A conscious selection of fat sources in the diet can therefore make a significant contribution to a healthy cardiovascular system [5].

What types of fatty acids exist?

As mentioned at the beginning, fatty acids consist of a hydrocarbon chain and a carboxyl group. Due to their different chemical structure, they are divided into different categories:

Saturated fatty acids
The chemical structure of a fatty acid that is saturated is characterized by the fact that it has no double bonds between the carbon atoms in its chain. This property gives it special physical characteristics, such as the fact that it is usually solid at room temperature. In nature, saturated fatty acids are often found in animal products, but also in some plant sources.
There are various types of saturated fatty acids that differ in their chain length. Some well-known examples are butyric acid, which is mainly found in dairy products and has only four carbon atoms), palmitic acid with 16 carbon atoms, which is found in both palm oil and animal fats, and stearic acid with 18 carbon atoms, which is mainly found in beef tallow and cocoa butter.

Unsaturated fatty acids
Unsaturated fatty acids form an important category of fatty acids that are characterized by at least one double bond in their carbon chain.
The group of unsaturated fatty acids is further divided into two subgroups: monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs).

• Monounsaturated fatty acids have a single double bond in their carbon chain. This structure gives them special properties, such as the fact that they are usually liquid at room temperature. PUFAs are often found in vegetable oils. Well-known examples are oleic acid, which is found in olive oil, avocados and nuts, and palmitoleic acid, which is found in macadamia nuts.
  A significant health benefit of PUFAs is their ability to lower LDL cholesterol levels while increasing HDL cholesterol levels, which can have a positive effect on heart health.
• Polyunsaturated fatty acids are characterized by two or more double bonds in their carbon chain. Like PUFAs, they are liquid at room temperature, but their structure makes them more susceptible to oxidation.
  PUFAs include important fatty acids such as linoleic acid (an omega-6 fatty acid), which is found in sunflower oil and corn oil, and alpha-linolenic acid (an omega-3 fatty acid), which is found in linseed oil and walnuts. The long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are mainly found in fatty fish, are also particularly noteworthy.
  The division of PUFAs into omega-3 and omega-6 fatty acids is based on the position of the first double bond, counted from the methyl end of the carbon chain. This distinction is important because omega-3 and omega-6 fatty acids have different physiological effects in the body and should be in a balanced ratio to each other.

Trans fatty acids
Trans fatty acids form a special category within the fatty acids. These are unsaturated fatty acids that are characterized by at least one double bond in a trans configuration. This special structure gives them unique properties that distinguish them from other unsaturated fatty acids.
Interestingly, trans fatty acids occur naturally in small amounts in dairy products, where they are produced by bacterial processes in the stomachs of ruminants. However, the majority of trans fatty acids found in our diet are mainly produced during the industrial hardening of vegetable oils, a process used to improve the shelf life and consistency of foods.
Trans fatty acids have attracted particular attention in nutritional science and the public health debate in recent decades, as they are considered to be particularly unhealthy. The reason for this lies in their double negative effect on cholesterol levels: they can both increase LDL cholesterol levels (the “bad” cholesterol) and lower HDL cholesterol levels (the “good” cholesterol). This combination is associated with an increased risk of cardiovascular disease. 

Medium-chain fatty acids
Medium-chain fatty acids (MCTs) form a special group within the saturated fatty acids, which are characterized by a chain length of 6 to 12 carbon atoms. This specific structure gives them unique properties that distinguish them from long-chain fatty acids. A major advantage of MCTs is their faster absorption and metabolism in the body. This means that they can be used more efficiently as an energy source. In nature, MCTs are mainly found in coconut oil and palm kernel oil, making these oils popular sources of MCTst.
In recent years, MCTs have attracted increasing interest in nutritional science and medicine. Researchers are intensively investigating their potential benefits for energy metabolism and weight control. There is evidence that MCTs can boost metabolism and help with weight regulation. These properties make them an interesting subject of research, particularly in the context of dietary strategies for weight control and improving metabolic health [6].

What role do essential fatty acids play?

Essential fatty acids play an important role in human nutrition and health. These special fatty acids are characterized by the fact that the human body cannot produce them itself.

It is therefore essential to consume them through food in order to maintain various vital functions in the body. Essential fatty acids include linoleic acid, an omega-6 fatty acid, and alpha-linolenic acid, an omega-3 fatty acid.

Why omega-3 fatty acids and omega-6 fatty acids are important for the body?

Omega-3 and omega-6 fatty acids are of great importance for health. Both fats are polyunsaturated fatty acids and offer specific health benefits.

Omega-3 fatty acids are mainly found in oily fish and are known for their anti-inflammatory properties. They can reduce the risk of cardiovascular disease by positively influencing blood pressure and triglyceride levels in the blood, among other things. They also play an important role in brain development and function [7].

Omega-6 fatty acids are also important for the body. Among other things, they contribute to brain function and are important for growth.

Which foods contain a lot of fats?

Fatty acids are found in a variety of foods.

Saturated fatty acids are mainly found in animal products and some tropical oils:

• Meat, especially red meat such as beef, lamb and pork, contains a high proportion of saturated fatty acids.
• Dairy products such as whole milk, butter, cheese and cream
• Coconut and coconut oil
• Palm oil

Monounsaturated fatty acids are found in many vegetable oils and fruits:

• Olive oil
• avocados
• nuts
• Rapeseed oil

The unsaturated fatty acids, including the important omega-6 and omega-3 fatty acids, are found in: 

• Fatty fish such as salmon, mackerel, herring and sardines
• Linseed oil and linseed
• Walnuts
• Sunflower oil
• Chia seeds and hemp seeds
• Soy and soy products

When should I take fatty acid supplements?

A varied and nutritious diet is healthy and remains the best way to provide our bodies with the necessary fatty acids. In certain cases, such as vegans or people with an increased risk of cardiovascular disease, omega-3 supplements may be useful after consulting a doctor.

Sources

[1] https://pubmed.ncbi.nlm.nih.gov/26177664
[2] http://laboratoire-shigeta.com/inner-care-role-of-fatty-acids-in-the-body
[3] https://www.eufic.org/facts-on-fats-dietary-fats-and-health
[4] https://www.aatbio.com/what-are-the-functions-of-fatty-acids
[5] https://www.aafp.org/p345
[6] https://pubmed.ncbi.nlm.nih.gov/32144120
[7] https://www.aok.de/wie-gesund-sind-omega-3-fettsaeuren