Which Fatty Acid Decreases Inflammation and How It Works

December 9, 2025 •

3 min read

Research consistently shows that omega-3 fatty acids possess potent anti-inflammatory properties, with some studies highlighting their role in reducing chronic inflammation linked to various illnesses, including heart disease. While the omega-6 fatty acid arachidonic acid is often associated with pro-inflammatory mediators, it's the omega-3 family, specifically EPA and DHA, that is known for its ability to decrease inflammation.

Quick Summary

Omega-3 polyunsaturated fatty acids (PUFAs), particularly EPA and DHA from marine sources, are highly effective at combating inflammation. These fatty acids act on the cellular level to reduce pro-inflammatory signals and produce anti-inflammatory molecules, contributing to the resolution of chronic inflammation.

Key Points

Omega-3 Fatty Acids are Anti-Inflammatory: Specifically, EPA and DHA found in marine sources are potent anti-inflammatory agents.
Inhibits Pro-Inflammatory Signals: EPA and DHA help suppress the production of pro-inflammatory molecules, such as certain eicosanoids derived from omega-6 fats.
Promotes Inflammation Resolution: Omega-3s are precursors to Specialized Pro-resolving Mediators (SPMs), like resolvins and protectins, which actively turn off the inflammatory response.
Rich Dietary Sources of EPA/DHA: The best food sources include fatty fish (salmon, mackerel) and algal oil, which is a vegan alternative.
Balanced Omega-3 to Omega-6 Ratio is Key: The modern Western diet often has an imbalance with too many pro-inflammatory omega-6s; increasing omega-3 intake helps restore a healthier ratio.
Mechanisms are Cell-Deep: Omega-3s influence inflammation at the cellular level by altering cell membrane composition and inhibiting key transcription factors like NF-κB.
Supplements Provide Consistent Doses: For those with low fish intake, supplements from fish oil or algae are a reliable way to ensure adequate EPA and DHA.

The Anti-Inflammatory Power of Omega-3s

Omega-3 fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are key players in reducing inflammation. As essential fats, our bodies can't produce them efficiently from the precursor ALA, requiring us to get them through diet or supplements. Their ability to modulate the body's inflammatory response provides significant benefits for managing or preventing chronic inflammatory conditions.

How Omega-3s Combat Inflammation on a Cellular Level

EPA and DHA work through several mechanisms to exert their anti-inflammatory effects at the cellular level. They integrate into the membranes of inflammatory cells, influencing their function and signaling.

Direct Mechanisms of Anti-Inflammatory Action

Competitive Inhibition: EPA and DHA compete with the omega-6 fatty acid arachidonic acid (ARA) for enzymes that produce signaling molecules. Higher omega-3 levels lead to reduced production of pro-inflammatory eicosanoids from ARA and the creation of less inflammatory alternatives.
Production of SPMs: EPA and DHA are precursors to Specialized Pro-resolving Mediators (SPMs), such as resolvins and protectins. These molecules actively promote the resolution of inflammation and aid the healing process.
Gene Expression Inhibition: DHA can inactivate NF-κB, a protein complex involved in inflammatory gene expression. This action helps control chronic inflammation associated with various diseases.

Food Sources for Anti-Inflammatory Fatty Acids

Consuming foods rich in EPA and DHA is an effective way to gain their anti-inflammatory benefits. Algae-based supplements are an option for those who don't eat fish.

Rich Sources of EPA and DHA

Oily Fish: Salmon, mackerel, sardines, herring, and anchovies are excellent dietary sources.
Algal Oil: Provides pre-formed DHA and EPA for vegans and vegetarians.
Fortified Foods: Some products like eggs, yogurt, and milk are fortified with DHA.

Plant-based ALA (alpha-linolenic acid) found in foods like walnuts and flaxseeds has limited conversion to EPA and DHA in the body, so relying solely on these sources may not provide sufficient anti-inflammatory effects.

Comparison: Omega-3 vs. Omega-6 Fatty Acids

Understanding the roles of omega-3 and omega-6 fatty acids is crucial. A balanced ratio is important, but Western diets often have excessive omega-6s.


Feature	Omega-3 (EPA, DHA)	Omega-6 (Arachidonic Acid)
Inflammatory Effect	Anti-inflammatory and pro-resolving	Precursor to pro-inflammatory mediators
Metabolite Action	Produces less potent eicosanoids and potent resolvins	Produces potent pro-inflammatory eicosanoids
Key Dietary Sources	Fatty fish, algal oil, walnuts, flaxseed	Vegetable oils (corn, soy), processed foods, meat
Cell Membrane Role	Increases membrane fluidity, displaces omega-6	Dominant fatty acid in inflammatory cells in Western diets
Effect on Gene Expression	Inhibits NF-κB, reduces inflammatory gene transcription	Promotes NF-κB activation, stimulates inflammatory gene expression

Practical Tips for Increasing Anti-Inflammatory Fat Intake

Eat Oily Fish Regularly: Aim for at least two servings per week.
Include Plant-Based Omega-3s: Add sources like flaxseed, chia seeds, and walnuts, but be aware of the low ALA conversion.
Choose Healthier Oils: Opt for olive oil and avocado oil over high omega-6 vegetable oils.
Consider Supplementation: Fish oil or algal oil supplements can help ensure adequate EPA and DHA intake, especially for those with low fish consumption.

Conclusion

In conclusion, EPA and DHA are the primary fatty acids known for their ability to decrease inflammation. They work by inhibiting pro-inflammatory pathways and promoting the resolution of inflammation. Increasing intake of these omega-3s through marine sources or high-quality supplements can help counteract chronic inflammation. A balanced diet focusing on EPA and DHA-rich foods while moderating omega-6 intake is crucial for an anti-inflammatory approach. Consulting a healthcare professional before starting supplements is recommended, particularly with existing health conditions or medications.

What fatty acid decreases inflammation?

Answer: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are long-chain omega-3 fatty acids, are the primary fatty acids known to decrease inflammation.

Frequently Asked Questions

The primary fatty acids that reduce inflammation are the long-chain omega-3s, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are predominantly found in marine life.

Omega-3s reduce inflammation by replacing the more inflammatory omega-6s in cell membranes, producing less potent inflammatory eicosanoids, and acting as precursors to specialized molecules called resolvins and protectins that actively resolve inflammation.

The best food sources include oily fish such as salmon, mackerel, and sardines. For vegetarians and vegans, algal oil supplements provide pre-formed EPA and DHA, while plant sources like flaxseed and walnuts contain ALA, which has a low conversion rate.

Yes, studies have shown that supplementation with EPA and DHA can help reduce the symptoms of inflammatory conditions such as rheumatoid arthritis, including reducing joint pain and stiffness.

Yes, while ALA is a beneficial fatty acid, its conversion rate to the more potent anti-inflammatory EPA and DHA is very low in the human body. For a stronger anti-inflammatory effect, marine sources or algal oil are more effective.

It is a common misconception that all omega-6s cause inflammation. While one type, arachidonic acid, is a precursor to some pro-inflammatory molecules, many studies show no increase in inflammatory markers from moderate omega-6 consumption. The key is maintaining a healthy balance with omega-3s.

The effective dose can vary, but research suggests that intakes greater than 2 grams per day of EPA and DHA combined may be required to achieve significant anti-inflammatory effects in adults. It is best to consult with a healthcare professional before starting any new supplement regimen.