Omega-6 is an essential fat. Without omega-6, cell membranes, skin barriers, hormone production, and the immune system cannot function properly. Yet omega-6 has become one of the most problematic nutrients in the modern diet. Not because it is harmful in itself, but because the amount, form, and context have changed in a way that the body is not biologically adapted for.
From evolutionary balance to modern imbalance
Omega-6 as inflammatory raw material
The most common omega-6 fatty acid in the diet is linoleic acid. In the body, it is further converted to arachidonic acid, which serves as the raw material for a series of signaling molecules that control inflammation, pain, immune responses, and blood clotting. These signals are absolutely essential in acute situations, such as infection or tissue damage.
The problem arises when the same system is kept activated over a long period of time. In a chronic excess of omega-6, there are always plenty of building blocks for inflammation-driving signals, while the body’s ability to end inflammation is weakened.
Inflammation in itself is not something negative. It is a vital defense system. But when inflammation becomes low-grade and chronic, its role in the body changes. Instead of being healing, it becomes burdensome. A high intake of omega-6, combined with a lack of omega-3, contributes to this type of low-grade inflammation that is today linked to many of our most common lifestyle-related conditions. Insulin resistance, cardiovascular disease, pain, autoimmunity and neurodegenerative diseases.
The brain and nervous system – especially vulnerable to fat imbalance
The brain is particularly sensitive to fat balance. The membranes of nerve cells are largely made up of fatty acids, and their composition affects how signals are transmitted between cells. When omega-6 predominates at the expense of omega-3, the properties of the membranes change, which can affect receptors, neurotransmission and nervous system regulation.
This can contribute to increased inflammation in the brain, poorer stress tolerance, and impaired cognition. Many experience this as brain fog, mental fatigue, or difficulty recovering from stress, rather than as a clear medical condition.
Oxidative stress and fat quality
An additional dimension is oxidative stress. Omega-6 fatty acids, especially linoleic acid, are very sensitive to oxidation. Industrial refining, long-term storage and heating produce oxidized fats and lipid peroxides that can damage cell membranes and burden the body’s detoxification system. This increases the need for antioxidants and can contribute to an environment where cells are exposed to continuous oxidative stress. It is therefore not only the amount of omega-6 that is relevant, but also its quality and how it has been handled.
Omega-3 and omega-6 compete biologically
An important, but often overlooked, aspect is that omega-3 and omega-6 do not act independently of each other. They compete for the same biological space in the body. Both fatty acids use the same enzyme system to be converted into biologically active signaling molecules and are built into the same cell membranes. Therefore, when the intake of omega-6 is high, it effectively takes space, both enzymatically and structurally, from omega-3.
This means that a high omega-6 intake not only drives inflammatory processes in itself, but also impairs the body’s ability to use omega-3 effectively. The balance between these fatty acids thus determines which type of signals the cells primarily produce: inflammatory or anti-inflammatory.
The fat balance also affects the properties of cell membranes. Cell membranes are dynamic structures whose elasticity determines how effectively cells can receive signals and communicate with their environment. With a high intake of omega-6, especially in combination with a lack of omega-3, the membranes become more sensitive to oxidation and prone to inflammation. This impairs their elasticity and function, which affects the cells’ signaling, stress tolerance and recovery ability.
How do we know if we are consuming too much omega-6?
For most people, a high omega-6 intake is not a matter of conscious choice. Industrial seed oils are widely used in ready-to-eat foods, breads, sauces, spreads and snacks, often without the consumer being aware of it. Although the ingredient list formally reports which oils are included, in practice the consumer lacks the information necessary to understand the biological consequences of the fat.
Under current EU regulations, foods must declare total fat and the amount of saturated fat, but there is no obligation to report how much omega-6 or omega-3 a product contains, nor the relationship between them. In order to assess your omega-6 intake, you therefore need not only to read the ingredients list, but also to know which fatty acids different oils are dominated by and in what proportions they are used. This is not something that can reasonably be expected of the average consumer.
Hidden and obvious sources
Restaurant food is another significant source. Dishes perceived as healthy are often cooked in omega-6-rich oils, sometimes at high temperatures and with recycled oil, which further increases oxidation.
Margarines and plant-based butter alternatives also contribute to the imbalance. Although they are often marketed as heart-healthy, in practice they are often based on refined seed oils and contain high levels of omega-6. Even so-called health snacks such as protein bars, nut bars and seed crackers can contribute more than you think, as they combine omega-6-rich ingredients with added vegetable oils in concentrated form.
The most common criminals
Sunflower oil is very rich in linoleic acid and one of the largest sources of omega-6 in both the home and food industries.
- Corn oil, which is commonly found in processed foods and restaurant kitchens, has a high omega-6 content.
- Soybean oil is one of the world’s most widely used cooking oils, especially in ready-to-eat foods, sauces and snacks.
- Margarines and plant-based “butter” alternatives are often based on several refined seed oils with high omega-6 content.
- Chips and other snacks fried in vegetable oil combine high omega-6 content with oxidation from heating.
Good option
Sunflower oil, corn oil and soybean oil can in practice be replaced by fats that the body is much better adapted to. Extra virgin olive oil is one of the most well-studied alternatives and is particularly well-suited for cold use and lighter cooking.
For higher temperatures, more saturated and heat-stable fats are often a better choice. Butter, ghee, coconut fat and animal tallow are particularly suitable here, as they contain very little polyunsaturated fat and are therefore less sensitive to oxidation when heated.
Avocado oil is another useful alternative. It is rich in monounsaturated fat, relatively heat-stable, and contains significantly less omega-6 than many seed oils. For those who want to cook with a neutral flavor while still avoiding large amounts of omega-6, avocado oil can be a convenient middle ground between olive oil and more saturated fats.
Restaurant food is harder to influence, but in the home kitchen, fat choices make a big difference over time. Cooking more from scratch and using olive oil, butter, ghee, coconut oil, tallow, or avocado oil significantly reduces your exposure to omega-6-rich oils. When eating out, simple choices like avoiding fried foods and asking for sauce on the side can help keep your overall load lower.
Margarines and plant-based spreadable “butter” alternatives can be replaced with natural fats such as butter, ghee, coconut oil or olive oil. These fats are less processed, more stable and closer to the fats that humans have historically consumed.
When it comes to snacks and meals, boiled eggs, yogurt, leftovers from previous meals, fruit or small amounts of nuts (macadamia, hazelnuts, cashews) provide nutrition without adding concentrated sources of omega-6.
Balance, not elimination
Perhaps the most overlooked factor, however, is not the amount of omega-6 per se, but the lack of omega-3 as a counterbalance . Even a moderate intake of omega-6 can become problematic when omega-3 intake is low. Omega-3 is needed to form signaling molecules that actively suppress and terminate inflammation. Without these signals, inflammatory processes risk becoming prolonged and difficult to regulate. The fat balance in the cell membranes then slowly but consistently shifts in a more inflammatory direction.
It is therefore important to emphasize that the solution is not to eliminate omega-6 completely. Omega-6 is essential for life and fulfills important functions in the body. The problem arises when the intake becomes disproportionately high and when there is a lack of sufficient protective factors. Health here is not about demonizing a single nutrient, but about restoring biological balance.
When the fat balance is improved through less industrial fats, more clean food and better access to omega-3 – the basic environment of the cells changes. Inflammatory processes become easier to regulate, the nervous system has better conditions for recovery and the body can use its own reparative mechanisms more effectively.
How should it be done – practically?
Read the article “Fat in the shopping cart” for tips on how to do it in everyday life.
Reference
Runcen Zu et al (2025) Mode and Mechanism of Action of Omega-3 and Omega-6 Unsaturated Fatty Acids in Chronic Diseases, Nutrients https://doi.org/10.3390/nu17091540
Rupa Health (2025), Omega-3s vs. Omega-6s: Balancing the Scale for Optimal Health in Clinical Practice. https://www.rupahealth.com/post/omega-3s-vs-omega-6s-balancing-the-scale-for-optimal-health-in-clinical-practice
