Omega-3 and Omega-6 Fatty Acids
Regarding omega-3 and omega-6 fatty acids, the ratio between them is crucial. The modern lifestyle and dietary habits that have developed over the last decades have led to an imbalance in their intake. Various diseases have been associated with this imbalance.
Basics of the Cell Membrane Bilayer
Biological membranes are primarily composed of lipids and proteins. They separate individual cells and organelles and regulate the transport of substances. Many biochemical processes take place at membrane level. For instance, nerve impulses are processed and transmitted by the membranes of nerve cells, while hormones and nutrients are recognised and transported by specific membrane receptors. The composition of membrane lipids is key to membrane stability and fluidity. The higher the proportion of unsaturated, particularly polyunsaturated fatty acids (PUFAs), the more active the membrane – and therefore the cell.
Omega-3 Fatty Acids
Omega-3 fatty acids are primarily incorporated into the cell membranes of the eyes and brain and serve as precursors for the synthesis of anti-inflammatory eicosanoids. This is why they are generally considered to have anti-inflammatory properties. They also help lower blood pressure, dilate small blood vessels, inhibit platelet aggregation, and improve blood flow. A high intake of omega-3 fatty acids can be achieved by consuming fish and algae. The use of cold-pressed, unrefined plant oils (e.g. chia, flaxseed, camelina, hemp, walnut, and rapeseed oil) – preferably organic – as well as consumption of wild game and grass-fed meat, also contributes to omega-3 intake.
Functions and Effects of Omega-3 Fatty Acids
- Anti-inflammatory
- Antiarrhythmic
- Vasodilatory (thus lowering blood pressure)
- Antithrombotic
- Immunomodulatory
- Enhance membrane fluidity
- Crucial for healthy neural development
- Help reduce triglyceride levels
Fish may contain heavy metals. As an alternative, certified fish oil or algae oil supplements can be used.
Effectiveness of Omega-3 Fatty Acids in Disease
The cardioprotective effect is the most well-known and well-documented benefit of omega-3 fatty acids. These fatty acids lower triglyceride levels and increase HDL cholesterol. They reduce blood pressure, dilate small blood vessels, inhibit platelet aggregation, and improve blood flow. They have also been shown to stabilise carotid plaques. The most important cardioprotective effect is their antiarrhythmic action.
Omega-3 fatty acids also show a positive impact on mental health. Recent studies have demonstrated that omega-3 supplementation may help alleviate symptoms of schizophrenia, bipolar disorder, depression, and ADHD.
Remarkable results have also been observed in the treatment of rheumatic joint diseases, such as rheumatoid arthritis. Fish oil or PUFAs have been shown to reduce morning stiffness, the number of painful or swollen joints, joint pain intensity, and time to fatigue within a few weeks. This leads to a reduced need for non-steroidal anti-inflammatory drugs (NSAIDs).
Omega-6 Fatty Acids
Omega-6 fatty acids (Omega-6 FAs) are mainly incorporated into the cell membranes of heart, liver, and nervous tissue. They serve as precursors for predominantly pro-inflammatory eicosanoids. Therefore, they are generally considered to have inflammation-promoting properties. Nevertheless, omega-6 FAs are essential for maintaining homeostasis in eicosanoid metabolism and other lipid modulators. Omega-6-rich feed is widely used in industrial animal farming (e.g. grains, soy), which in turn leads to high omega-6 content in animal-based food products (e.g. meat, dairy).
Functions and Effects
- Pro-inflammatory
- Vasoconstrictive (thus increasing blood pressure)
- Prothrombotic
- Promote tumour tissue growth
- Increase excretion of secondary bile acids in the intestines, which promotes colorectal cancer development
Symptoms of Deficiency and Possible Consequences
- Impaired skin function, eczema, delayed wound healing, hair loss
- Cardiovascular complaints, anaemia
- Immune system: increased susceptibility to infections, heightened risk of atopy
- Children/adolescents: behavioural issues, growth disorders
- Impaired cognitive function
- Miscarriages
- Degeneration of liver and kidney tissue
Omega-3 vs. Omega-6 – The Balance Matters
Due to changes in modern dietary habits, a severe imbalance between omega-3 and omega-6 intake has developed in recent decades. Excessive omega-6 intake can displace omega-3 molecules in the membranes of heart muscle cells, which increases the risk of ventricular fibrillation.
Diseases associated with a disturbed omega-3/omega-6 balance include:
- Coronary heart disease
- Cardiac arrhythmias
- Inflammatory joint diseases (rheumatoid arthritis)
- Atopic diseases (asthma, chronic bronchitis, eczema, psoriasis)
- Multiple sclerosis, lupus erythematosus
- Inflammatory bowel diseases (Chron’s disease, ulcerative colitis)
- Mental health disorders (depression, schizophrenia, ADHD)
- Type 1 diabetes
The omega-3 index is a measure of the body’s supply of the omega-3 fatty acids docosahexaenoic and eicosapentaenoic acid, and indicates their proportion among all fatty acids. A low index value correlates with an increased risk of coronary heart disease and sudden cardiac death. An index above 8% is associated with good cardioprotective effects. Numerous epidemiological studies have shown that a diet rich in fish can reduce the incidence of cardiovascular disease because of its high omega-3 content.
