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Summary
Fat often gets a bad reputation. But what many people don’t realize is that fatty acids, the main components of fats, are actually essential for our bodies. As with most things in nutrition, it all comes down to quality and balance.
In this article, we’ll explore what fatty acids really are, why they matter, and how to tell the “good” ones from the less beneficial ones. You’ll learn about the different families of fatty acids, where they come from in the diet, and how they influence our health. We’ll also look at how they function inside the body, their key roles, what to check for when choosing high-quality fatty acids, and how to include them wisely in your diet.
Whether you’re simply curious, passionate about nutrition, or working in the nutrition field, this article will give you clear, useful answers.
Fatty acids are part of the lipid family, commonly referred to as “fats” in our diet. From a scientific point of view, a fatty acid is a chain of carbon atoms with an “acid” group at one end.
In the body, most fatty acids are found as triglycerides (three fatty acids attached to a glycerol molecule) which serve as a way to store energy. Fatty acids are also part of phospholipids, the molecules that make up the membranes of our cells.
Energy storage: Fatty acids are used to store energy (calories) when the body has more than it needs. Once converted into fatty acids, this highly concentrated energy is stored in fat reserves. When the body requires energy (between meals or during physical activity), it can tap into these reserves: triglycerides are broken down again into free fatty acids and glycerol. Cells then use these fatty acids to produce energy that the body can use.
Structural role: Fatty acids are also part of phospholipids, the main components of cell membranes. These molecules help the membrane stay flexible yet stable, and they control what can enter or leave the cell.
Body regulation: Depending on their type, some fatty acids serve as building blocks for “messenger” molecules. These molecules help regulate important body functions, such as inflammation, blood clotting, and the activity of certain genes.
Fatty acids can be classified according to two main criteria: the structure of the molecule (the number of double bonds in the chemical chain, which act like hinges) and whether the body needs to get them from the diet or can produce them on its own.
Based on structure:
Saturated: no carbon-carbon double bonds. This makes them rigid, which is why they are usually solid at room temperature.
Examples: palmitic acids, found in coconut oil and butter.
The body can produce them, but eating too much saturated fat can cause cholesterol issues.
Monounsaturated: one double bond. They are more flexible than saturated fats and are liquid at room temperature.
Example: oleic acid (omega-9), abundant in olive oil. This is why olive oil stays liquid at room temperature.
Polyunsaturated: multiple double bonds. These fats are even more flexible and remain liquid even at cooler temperatures.
Examples: omega-3 and omega-6, which help oils stay liquid even in the fridge.
Trans: unsaturated fats that have been modified, often through industrial processes, which changes their geometric structure. This alteration affects how they behave in the body.
Based on physiological need:
Essential: these fatty acids cannot be produced (or not in sufficient amounts) by the body, so they must come from food or supplements.
Omega-6: linoleic acid is the main essential omega-6. The body cannot make it, so it must come from the diet.
Omega-3: alpha-linolenic acid (ALA) is the main essential omega-3. The body can convert ALA into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are very important for heart and brain health. However, this conversion isn’t efficient enough, especially for DHA. That’s why it’s helpful to get EPA and DHA directly from fatty fish, algae oils, or supplements such as Lecimarine®.
Non-essential: the body can usually produce these fatty acids. However, during growth, illness, or aging, production may not be enough.
Omega-3: Essential for the brain, vision, and nervous system. EPA and DHA, two key types of omega-3, play a protective role for the heart (reducing triglycerides and lowering blood pressure) and support brain health.
Omega-6: Also essential. They serve as building blocks for cell membranes and help produce molecules involved in inflammation and blood clotting. However, too much omega-6 compared to omega-3 can create an imbalance. Both omega-3 and omega-6 are processed by the same enzymes in the body, so an excess of omega-6 limits the conversion and effectiveness of omega-3. This imbalance is common because most commercial vegetable oils are high in omega-6, while omega-3 intake is often lower.
Lower “good” cholesterol (carried by HDL, which transports excess cholesterol back to the liver for elimination)
Promote inflammation
Consuming trans fats increases the risk of heart disease. Most trans fats in the diet come from industrial sources, and national and international health authorities recommend minimizing their intake.
Energy production: Fatty acids can be oxidized in cells to produce adenosine triphosphate (ATP), the energy the body needs to function.
Membrane construction: Some fatty acids are used to make phospholipids, the main components of cell membranes, which maintain fluidity and protect cells.
Signaling molecules: Polyunsaturated fatty acids like omega-3 and omega-6 can be converted into eicosanoids, molecules that send signals to cells to regulate processes like inflammation, blood clotting, and blood vessel constriction.
Storage: Excess fatty acids can be reassembled into triglycerides and stored in fat tissue for later use.
Regulation:
Some fatty acids influence gene expression. They can activate proteins that control how fats are used by cells, whether for immediate energy, storage, or cholesterol production.
Fatty acids are not a problem for our bodies. On the contrary, they are essential components of our diet and physiology: they help store energy, build cell structures, and regulate many biological processes. However, not all fatty acids are equal. Some, like omega-3s, are very beneficial, while others (trans fats or excessive saturated fats) can pose health risks. It is therefore important to consume quality fats in a balanced way and pay attention to the origin of the products (extraction method, storage, contamination).
⚠ Disclaimer: This article is for informational purposes only and does not replace the advice of a healthcare professional.
